Monarch flex budgeting explained: fixed, flexible and non-monthly spending

Two budgeting styles in one app

Monarch offers two ways to budget. Category budgeting sets a limit for each category, such as groceries, restaurants or utilities. Flex budgeting groups spending into three buckets, fixed, flexible and non-monthly, and focuses on one number: how much is left for flexible spending. Monarch's blog calls flex one of its core budgeting types and says you can switch between category and flex budgets in the budget settings.

Transactions are still categorized the same way in both styles. What changes is what you are asked to plan and watch: twenty separate limits, or one flexible total plus a set of committed costs.

This is research from official pages read on 30 October 2026, not firsthand testing. We have not opened these accounts or run the features described; help pages change, so confirm the live page before you rely on a detail.

The three buckets and goals

These definitions and examples come from Monarch's flex budgeting post, originally published 17 November 2024 and updated 30 April 2026.

Worked example: converting a 20-category budget

This invented household takes home $7,000 a month and currently budgets 20 categories. Converting to flex means assigning each category to a bucket, turning yearly costs into monthly set-asides, and moving savings into goals. Nothing about the household's spending changes; only the number they watch does.

Fixed categories total $3,745: rent $2,100, car payment $380, car insurance $140, utilities $210, phone $90, internet $70, childcare $650, streaming $45 and gym $60. Non-monthly set-asides total $485: car registration $20 (from $240 a year), holiday gifts $75 ($900 a year), travel $200 ($2,400 a year), repairs $100 ($1,200 a year) and medical deductible $90 ($1,080 a year). Goals total $900: $500 to the emergency fund and $400 to retirement. The six flexible categories (groceries $900, dining $300, gas $220, shopping $250, entertainment $120 and personal care $80) total $1,870.

Flex number: $7,000 minus $3,745 minus $485 minus $900 equals $1,870 a month, or about $434.88 a week using Monarch's 4.3 divisor. Instead of six flexible limits, the household watches one: if dining runs $100 over, groceries or shopping have to come in $100 under for the month to stay on plan.

When each style suits a household

Monarch's own comparison is candid about the trade-off. Flex is less work to plan and gives room in how money is spent but less detail about where it goes; category budgeting gives detail but its strict limits can feel rigid.

Setting the flex number and common mistakes

Monarch says it calculates the flex number automatically once your buckets and goals are set up, and that you can also work it out by hand with its formula. For variable income its post advises recalculating the flex number each month, using expected income as the baseline. A practical starting point of our own: compare the result with what your flexible categories actually cost over the last three months before you commit to it.

• Misfiled fixed costs: a subscription left in Flexible makes the flex number look smaller than it is; move it to Fixed in Settings, Categories.
• Non-monthly without rollover: if rollover is not enabled on a non-monthly category, unspent set-asides do not carry forward and the bill arrives with nothing saved.
• Goals left out: if goal contributions are not subtracted, the flex number quietly includes your savings.
• Over-reading weekly figures: the 4.3 divisor is an average of about 4.33 weeks a month, so a month that contains five of your usual shopping days will run tighter than the weekly figure suggests.