Overview
Budget first
Sort every bill into needs, wants and debt. Waterline works out what you actually save, rather than asking you to guess it.
Find the day you go under.
Your monthly average hides the one date that matters. Waterline puts every payment on the day it actually lands, and shows you the lowest point before it arrives.
Previewing never touches your own plan.
No bank loginsStays on your device unless you sign inEncrypted when synced How we keep it safe
Forecast
A calendar that knows your balance
See each day's movement and the running balance beside it. Tap any date to drop in a one-off — a repair, a refund, a filing fee.
Debt
A debt plan you can live with
Pick a date to be debt-free and see the payment it takes. Then play that plan into your forecast, payment by payment, and check it never pushes you under zero.
Security
Your numbers stay yours
Waterline is built so the least possible ever leaves your hands — and what does is locked down.
- No bank connectionIt never asks for bank logins, card numbers or account numbers. You type only what you choose.
- On your device firstWithout an account, your plan lives only in this browser. Nothing about it is sent anywhere.
- Encrypted in transit and at restIf you sign in, your plan travels over HTTPS and is stored encrypted with AES-256.
- Locked to your accountRow-level security in the database refuses to hand one person's plan to anyone else.
- No ads, no trackersNo analytics, no advertising, no third-party cookies. Your plan is never sold or shared.
- Delete it any timeOne option in the account menu removes everything, from your account and this device.
Ready when you are
Try it with sample numbers, or start with your own. No sign-up needed.
Back to my overviewOverview
Everything you earn and everything you owe each month. This is where the forecast gets its numbers.
Forecast
See the day-by-day forecast
Starting point
where the forecast beginsMoney in
regular, repeating incomeMoney out
regular, repeating bills — one-offs live on the ForecastWhere the money goes
monthly equivalentYour target split
of take-home income70 / 20 / 10 is the realistic starting point when rent takes a large share of your pay. 50 / 30 / 20 is the textbook version. Debt payments are tracked separately — they come straight out of what you would otherwise save.
The month in one line
Forecast
Your budget played forward, day by day. Add the one-off things that don't repeat — a repair, a refund, a fee — straight onto the date they land.
Nothing to forecast yet
Add your income and bills on the Overview page and this fills in.
—lowest point
—days below zero
—left each month
balance
below zero
lowest point
Tap the chart to zoom and explore
Baseline lowest —
This plan lowest —
Calendar
SunMonTueWedThuFriSat
recurring
one-off
Tap any day for every payment and the balance
| Date | What moves | Change | Balance |
|---|
What-if
Copy your plan, change one thing, and see both lowest points side by side. Moving a bill a week later is often worth more than cutting anything.
Your scenarios
the one you pick is what every other page shows
this plan
baseline
lowest point
What changed
this plan against the baseline| Item | Baseline | This plan | Monthly difference |
|---|
Debt
Every balance in one place, ordered by what it costs you to keep — and what it takes to be rid of it.
What you owe
highest rate first — that is the one to attackDebtBalanceRate %MinimumCosts you
Clear it by
pick a finish line and see the payment it takesClear everything in
36 months
6 months6 years
Monthly payment needed
—
Total interest paid—
Total you pay back—
Versus minimums only—
Debt-free—
Put this plan into your forecast
see what paying it off does to your day-to-day balanceThe order they fall
at the payment above| Cleared | Debt | Rate | Balance now |
|---|
Report
Two pages that say where you stand, what the month looks like, and what the debt costs. Built from everything you have entered.