Calculator
Can I afford this?
You can be on budget for the month and still come up short on a Tuesday. The test isn't the average. It's the lowest week. This projects your balance forward and finds it. Recurna Flow does the same for your whole year.
Can I afford this?
Put in your balance, your pay, your bills, and the thing you're weighing. See your balance week by week for the next 12 weeks, and the lowest week, the one that decides it. No signup, no bank connection; the math runs right here.
Your lowest week is week 4 at $1,800: that clears your $500 floor with $1,300 to spare. This purchase fits.
Buying this lowers your lowest week by $1,400.
Recurna Flow
That's 12 weeks on one balance. The part a calculator can't show you is your whole year: every account, every bill, every what-if, redrawn the moment you change something.
Flow is in invite-only beta: apply once (reviewed weekly), and founding members get Pro free for a year, then $6/mo locked for two more.
Estimates only, not financial advice. A simple weekly projection from the numbers you enter: it spreads monthly bills evenly across the weeks, assumes your pay and bills repeat, and assumes your next pay lands within the next 7 days (paid less often than weekly? this can overstate the next few weeks until your first cheque actually lands).
How this math works
A month can look fine on average while one specific week still runs low. Pay usually lands in a lump, not evenly. This calculator spreads your monthly bills evenly across the weeks (a simplification: real bills often cluster on specific due dates) and projects your balance week by week to find the lowest point, because that trough is what actually decides whether a purchase fits, not the month-end total. Recurna Flow instead lays your actual bills on their actual due dates, so it can catch the weeks where several of them cluster together.
Why does the lowest week decide it, not the month-end balance?
A month can average out fine while a specific week still goes negative. Bills don't land evenly across the month. The week with the lowest projected balance is the one that actually determines whether the purchase is safe.
Why does timing matter more than the price?
The same purchase can be comfortable in a week with no other bills and tight in a week where several land together. Moving the purchase to a different week changes the outcome more than negotiating the price does.