Rolling Budget

A rolling budget, on this page, means a leftover rolls forward. Money you did not spend in a category is still in that category next month. Money you spent past the category is still missing next month. The calendar turning is not a reset.

The Consumer Financial Protection Bureau's Your Money, Your Goals cash flow budget tool, file dated 2018-11, does this with the whole week. Its week 1 sample starts at $250, adds $300 and $100, and subtracts $200, $35, and $15. The ending balance is $400, and that $400 is the beginning balance for week 2. Monarch Money's rollover article, updated August 14, 2026, does it inside one expense category. Any leftover amount carries into the next month. The formula is in the Monarch section below. The grocery month on this page is the same subtraction, so you can run it on paper.

Accountants use the same two words for a plan that stays a year long. AccountingTools, on May 20, 2026, says a rolling budget adds a new period when the most recent period is completed. That rule does not move an unspent grocery dollar. It has its own section, so the names stay apart.

Checked October 29, 2026. The prices in the apps section were read from the vendor pages linked at the end. A fact a page does not state is marked Not documented. The dollars below are an example household. They are not a quote of your grocery bill.

The steps

You need a category, a planned amount, and a written leftover. Writing down take-home pay and the fixed bills is the work before it. That earlier pass is on how to make a budget. This page starts once the category has a number.

1. Name the category and the planned amount before the month starts. The example uses groceries at $400. The planned amount is what you intend to add this month. It is not the cash already sitting there from last month.
2. Subtract what you actually spent. Planned minus actual is the leftover. A negative result is a leftover too. March at $400, with $340 spent, leaves $60. April at $460, with $510 spent, leaves negative $50. Ignoring the negative number is how next month lies.
3. Next month's available amount is the leftover plus the planned amount. The planned amount stays $400. Rollover does not rewrite it. April's available groceries are $60 plus $400, which is $460. May's available groceries are negative $50 plus $400, which is $350. That sum is what the category can spend. It is not a second pile of cash on top of the bank balance. The $60 was already unspent. The label kept it.
4. Cover a shortfall once. You can move money from another category this month, or you can let the shortfall roll. The same gap should not be both. A move that fills the negative $50, plus a rollover of that same negative $50, counts the dollars twice.

A worked example

Example household only. These are round numbers chosen so the arithmetic is easy to check. They are not a budget and not a recommendation. Groceries are planned at $400 each month. March starts with nothing rolled in.

$400 minus $340 is $60. $60 plus $400 is $460. $460 minus $510 is negative $50. Negative $50 plus $400 is $350. $350 minus $300 is $50. The rolls-out cell of one month is the rolled-in cell of the next. June would start at $50. That $50 is still groceries. It is not a new savings account.

A reset drops both the $60 and the negative $50. April would start at $400, and May would start at $400. The rolling lines are $460 and then $350 because the leftover and the shortfall both stayed. April's $510 against a reset of $400 would have been $110 over, and that $110 would have ended with April. On the rolling line, the $60 cushion absorbs $60 of that $110, and $50 remains. $110 minus $60 is $50. That is the same negative $50 in the table.

The whole week, from the CFPB sample. Starting balance $250, plus $300, plus $100, is $650. Expenses of $200, $35, and $15 add to $250. $650 minus $250 is $400. The tool's week 1 example says that $400 is now the beginning balance for week 2. That carry is one number for the whole week. It is not a grocery envelope. The $60 in the table stays in groceries. The other categories do not receive it. The checking balance does not rise by $60 because the category rolled. The cash was already there.

The 12-month habit

AccountingTools, May 20, 2026, uses rolling budget for a different rule. You add a new budget period when the most recent period is completed, so a business always has a budget that extends one year into the future. The page also calls that continuous budgeting. Its example starts as January through December. When January ends, the company adds the following January. The horizon still runs 12 months, from February through next January.

Becker's glossary, read October 29, 2026, describes the same habit. When a period ends, that period comes off the projection, and a new period of the same length is added. The glossary also calls this a continuous budget. A household can keep a list the same way: on the first of the month, write the month a year out, and drop the month that just ended. Adding next March does not put the unspent $60 from this March into April. The leftover and the horizon are two procedures. Running one does not run the other.

How it fits the budget you already use

An envelope can hold the leftover. Fill the envelope before you spend, and spend from that envelope. The fill, the empty envelope, and the paper-versus-digital difference are on envelope budgeting. Stuffing physical cash at the start of the month is cash stuffing. Vanguard does not say to empty an envelope because the month ended. Cash still in the grocery envelope is the $60. Dumping it back into an unnamed pile is a reset. That reset is a choice you add. It is not required by the envelope steps.

Budget vs actuals is the comparison that comes first. You still subtract what you spent from what you planned. The roll is what you do with that difference afterward. The sign difference between a gap and Remaining, and the choice to move money or change the plan, are on budget vs actuals. Turning the rollover on does not raise the planned $400 to $460. Available is the column that moves.

A zero gives every new dollar a job. Income minus the assignments equals zero. The worked month is on zero-based budgeting. The $60 already has a job: groceries. Assigning that same $60 to savings, while the grocery line still shows it, counts it twice. You can still assign the new paycheck down to zero and let last month's category balance stay. The zero and the carry are different steps.

A named bill can be built by letting the leftover roll. Annual insurance and a quarterly utility bill are not a surprise. The monthly division is on sinking funds. Monarch's rollover article uses that shape for a $200 bill every four months, set at $50 a month. Four unspent months roll to $200, and the payment brings the rollover back to $0. If you also move that same $50 into a separate savings line, you have two names for one set-aside.

Pay yourself first is a transfer at the start. A set amount leaves when you are paid. The steps are on pay yourself first. The $60 grocery leftover is not that transfer. It is unspent groceries. Moving it to savings on purpose is a new decision. Leaving it in groceries is the roll.

50/30/20 sizes this month's income. Needs, wants, and savings are three shares of take-home pay. The bucket lists are on the 50/30/20 budget rule guide. April's available groceries are $460, while the new assignment is $400. The percentage test looks at the new $400. The rolling test looks at $460. They answer different questions.

The balance until the next paycheck is a pace. That check is on how to calculate safe to spend. The $60 is inside a category. It is not a second copy of the safe-to-spend number.

Common mistakes

Resetting in your head. The table says April can spend $460. A shopper who remembers the planned $400, and forgets the $60, leaves $60 of groceries unused and then wonders where the month went. The reverse mistake spends the $400 and the $60 and also spends as if the bank balance were a fresh copy.

Dropping the negative. April's rolls-out cell is negative $50. May starts at $350, not at $400. A month that "starts clean" after an overspend has switched to a reset. Write that switch down. Otherwise May's $400 and the rolling $350 are two budgets.

The bank balance is the leftover. The CFPB sample carries $400 because that is the cash left for the whole week. The grocery table carries $60 inside one category. Looking at the checking account and calling all of it groceries spends the rent. The category leftover is the labeled part, not the pile.

Two names for the same dollars. The $60 inside April's $460, plus a $60 transfer to savings, plus a sinking-fund line of $60, is three uses of one leftover. Pick the job. The roll keeps the job the category already had.

Rolling the paycheck. Monarch's August 14, 2026 article says rollovers apply to expense categories only. They cannot be applied to income categories. The method on this page is a spending category. A paycheck that you treat as next month's income roll is a different rule, and that article does not provide it.

Adding a month and calling the leftover done. The 12-month habit drops March and adds next March. The grocery $60 is still a separate line. A year-long list with a category that resets has done the horizon and skipped the leftover.

Monarch Money

Monarch Money is the default comparison if you want a household dashboard and budgets that track actuals. It is the mainstream app in that comparison. Pen and paper holds the same subtraction. The rollover is a setting on an expense category. A button named rolling budget: Not documented on the pages checked for this guide.

The budget article, updated October 22, 2026, says the web budget page shows three columns: Planned, Actual, and Remaining. Category budgeting assigns every expense category a budget and tracks spending at the category level. Flex budgeting is the default: one flexible spending number, instead of a plan for every category. The first visit fills amounts from the average of the last six months. That average is history. The $400 on this page is a number you type. Transfer and Credit Card Payment categories are excluded from budgets and cash flow, so a transfer to your own savings, filed that way, will not show as spending.

The getting started article, updated October 27, 2026, says budgets reset monthly unless you enable rollovers. The tip on that page says a surplus or a shortfall carries into the next month when you turn rollovers on, using the gear icon next to a category. That article also says its setup steps apply to every Monarch subscription, Core and Plus. The pricing page does not list rollovers. Which plan includes them: Not documented on the pricing page.

The rollover article, updated August 14, 2026, states the arithmetic. Rollover from last month, plus planned this month, minus actual this month, equals the remaining rollover for next month. April in the example is that formula: $60 plus $400 minus $510 equals negative $50. The article's own example is different numbers. Last month was $25 over, so the rollover is -$25. Planned is $100. Actual is $50. -$25 plus $100 minus $50 is $25 left to roll. Rollovers continue for as many months as you leave them on. A month with a rollover shows a cycle icon next to the remaining number. On the web app the toggle is the gear icon on the category. On mobile it is the three dots while you are viewing the category.

The same article's bill example is a sinking fund built by the roll. A gas and electric bill of $200 is due every four months, so the monthly amount is $50. Turn on "Make this category a rollover fund," and the article says you can apply that $50 to future months. Month one rolls $50, month two $100, month three $150, and month four $200. Paying the bill brings the rollover back to $0, and the cycle starts again. You can also set a starting balance on the edit category screen if the category should open with more than this month's planned amount. The monthly division, without the app, is the sinking-funds guide linked above.

Rollovers apply to expense categories only. Income categories are out. The article also says you can turn a rollover on for a category in the fixed bucket, the non-monthly bucket, or the flex bucket, and you can turn it on for the flex bucket itself. For the fixed and non-monthly buckets, the rollover changes the Remaining amount on the category and on the bucket. For a category inside the flex bucket, the rollover changes that category's Remaining amount and does not change the overall flex bucket amount.

The household article, updated October 20, 2026, says one subscription covers the household. Each person has a login. The household shares one dashboard and the same budget. You cannot hide a bank account or a transaction once someone is in. The getting started article says to add household members, such as a spouse, partner, or parent, under that same subscription. There is still no free plan. A second person does not create one.

Price, read on monarch.com/pricing on October 29, 2026. There is no free plan. The pricing help, updated March 3, 2026, says Monarch only offers paid subscriptions, in US dollars, plus tax where it applies. Core is $14.99 a month, or $8.33 a month when billed $99.99 a year. Plus is $16.67 a month, billed $199.99 a year. Both plan cards say a free 7-day trial, then that price, and that a payment method is required. Cancel in settings before the trial ends. A month-to-month Plus price was not on the page. Not documented. Plus, on the pricing page, includes forecasting tools. A forecast that drops the month that ended and adds a new month: Not documented on the pricing page. Trial length, the annual price, and discounts are on Monarch Money pricing.

Monarch also publishes an MCP connector, updated October 22, 2026, for Core and Plus. Read-only is the default. Write access is separate, and you allow it. That connector is a way to ask about categories and rollovers you already have. It is not the leftover, and it is not a free plan.

Where FYN fits

FYN is our product, and it is last. The subtraction on this page is something you run. A leftover that rolls into the next month, a category rollover, or a 12-month rolling budget: Not documented on the pricing page. The pricing page lists an autopilot budget on Free and on Pro, next to the home screen and a spending map. That the autopilot budget carries a leftover forward: Not documented on the pricing page.

What the pricing page does list is the record of what you actually spent. Receipt photos and emailed receipts are one monthly count, 20 a month on Free and 200 a month on Pro. Apple Pay and Google Wallet purchases are logged as you pay, on Free and on Pro. Groceries, a bill you paid that way, and the purchases that make up the spent column show up as you pay them. Ask FYN is 20 questions a month on Free and 500 on Pro. You can ask about the receipts and the purchases you have saved, then compare that total with the planned amount you already wrote down.

The free plan is $0. It does not expire and does not ask for a card. It includes 1 household member on Free. You can start there without linking a bank. A read-only connector lets assistants such as Claude and ChatGPT read FYN data. The free plan includes 500 MCP calls a day. Pro includes 10,000 a day. The MCP docs say a free account does not sync bank accounts, so tools that read bank data return little or no data until a bank is linked. Linking a bank is not on the free plan.

Pro is $9.99 a month. Bank sync is Pro only, through Plaid, for up to 15 accounts. That is the feed that shows a charge that never produced a receipt photo, so the spent column can include it. The pricing page lists unlimited household members on Pro. Everyone shares the plan's limits. Household sharing is on the pricing page: 1 household member on Free, and unlimited household members on Pro. The pricing FAQ says a shared member can be an owner, a member, or view-only. The household page is the longer description of those roles. Monarch also publishes an MCP connector, on Core and Plus, read-only unless you allow write. Updated October 22, 2026. FYN is not the only one. The plan table is on pricing.

FAQ

Sources

Checked October 29, 2026. These are the pages behind the guide. A line marked Not documented is a fact the linked page does not state.

• CFPB Your Money, Your Goals cash flow budget tool, file dated 2018-11. The week 1 sample starts at $250, adds $300 and $100 for a total of $650, subtracts $200, $35, and $15, and ends at $400. That $400 is the beginning balance for week 2: Cash flow budget tool.
• AccountingTools, May 20, 2026. A rolling budget adds a new period when the most recent period is completed, so the plan still extends one year. The example runs January through December, then February through the following January. Also called continuous budgeting: Rolling budget definition.
• Becker glossary, read October 29, 2026. When a period ends, that period comes off the projection and a new period of the same length is added. Also called a continuous budget: Rolling budget.
• Take-home pay and fixed bills, before you pick the category amount: how to make a budget.
• An envelope that can still hold cash when the month ends: envelope budgeting.
• Assigning every new dollar until income minus assignments equals zero: zero-based budgeting.
• A monthly amount for a bill that does not come every month: sinking funds.
• A set amount moved when you are paid: pay yourself first.
• Needs, wants, and savings as three shares of this month's income: the 50/30/20 budget rule.
• The balance you have now, minus bills due before the next paycheck: how to calculate safe to spend.
• Monarch Core and Plus prices, the 7-day trial, and the payment method. Core $14.99 a month or $99.99 a year ($8.33 a month). Plus $199.99 a year ($16.67 a month). Plus lists forecasting tools. Rollovers are not named on this page: monarch.com/pricing.
• Monarch pricing help, updated March 3, 2026. Paid subscriptions only. Prices are in US dollars, plus tax where it applies: Pricing.
• Creating your budget in Monarch, updated October 22, 2026. Planned, Actual, and Remaining. Category and flex budgeting. Flex is the default. Transfer and Credit Card Payment are excluded from the budget: Creating your budget.
• Getting started with Monarch, updated October 27, 2026. Budgets reset monthly unless you enable rollovers. The setup steps apply to Core and to Plus. Household members sit under the same subscription: Getting started.
• Rollover budgets, updated August 14, 2026. Leftover in an expense category carries into the next month. The formula, the negative $25 example, and the $50 times four months gas and electric example. Income categories are excluded: Rollover budgets.
• Monarch for couples and households, updated October 20, 2026. One subscription, separate logins, one dashboard, the same budget. You cannot hide an account or a transaction: Monarch for Couples and Households.
• Trial length, annual price, and discounts, in one place: Monarch Money pricing.
• FYN pricing. Free is $0 and does not ask for a card. One household member on Free. Receipts 20 a month on Free and 200 a month on Pro. Apple Pay and Google Wallet purchases logged as you pay. Ask FYN is 20 questions a month on Free and 500 on Pro. Pro is $9.99 a month, with unlimited household members. Bank sync is Pro only, up to 15 accounts. A leftover that rolls, a category rollover, and a 12-month rolling budget are not on this page: pricing.
• FYN household roles. An owner, a member, or view-only: household.
• Monarch MCP connector, on Core and Plus, read-only unless you allow write. Updated October 22, 2026: Monarch MCP connector.
• FYN MCP docs. Read-only. 500 calls a day on the free plan and 10,000 on Pro. A free account does not sync a bank: MCP docs.