Built by Avyth · self-initiated, not client work
Plan a card payoff that survives the 0% promo expiring
Most payoff calculators treat a 0% intro card as free money forever. When the promotional rate ends the real schedule diverges sharply from what the calculator promised — usually at the moment the plan mattered most.
The real interface, with fictional demo data.
The approach
Enter cards as they actually are, promo expiry dates included. The schedule is worked from daily periodic rates and the cliff date, giving the month you are actually done and what avalanche saves over snowball in dollars. Everything runs in the browser; the figures are never sent anywhere.
Decisions
And what each one cost.
Model the cliff, not the headline rate
The promo expiry is the entire point. A calculator that ignores it is not simpler, it is wrong — and wrong in the direction that costs the user money.
State the assumptions next to the answer
Interest is posted monthly on the opening balance, deliberately a touch conservative against real average-daily-balance billing. Your lender's exact posting rules will differ, and the page says so beside the result instead of burying it.
Keep the figures on the device, and say so
Debt figures are about as personal as data gets. They are stored in your own browser so a plan survives a closed tab, the page tells you that before you calculate, and there is a control that clears them — which verifies the deletion actually happened rather than assuming it.
What it can't do
It works from the numbers you type. It does not connect to your bank, cannot see fees or a changed rate, and is a planning tool rather than financial advice.
How it was checked
Checked against hand-computed schedules including a promo expiring mid-plan, and the on-device storage claim was verified by entering a card and confirming what was written and that clearing removed it.
Live flow last exercised .
Something like this, for your work?
If you have a job that looks like this one — mechanical, repetitive, and currently done by a person — describe it and I'll tell you whether it's worth building.