Personal cash-flow forecasting
Your balance says you're fine.Ask it about September.
A bank balance is a photograph. Glideline carries it forward through everything you know is coming — the rent, the paycheck, the tax bill, the renewal you forgot about — and tells you the month it stops being enough.
One email when it opens up. Nothing else.
Runway
Clear for
2 months
Reserves today
$12,726.93
Reserve floor
$3,000.00
Lowest point
$686.93
Oct 2026
Clear through Sep 2026. Oct 2026 is the first month to end below your $3,000.00 reserve floor. 2 of the 13 months ahead are short.
A sample forecast. Yours is built from figures you record.
The same money, read two ways
What a balance says
$12,726.93
True, and comfortable-sounding. It says nothing about the deposit landing in eight weeks, or the tax bill before it, or that both fall in the same quarter as the annual renewals.
What a forecast says
2 months of runway
Same money, same day. You're clear until Oct 2026, when the reserves drop to $686.93 — and there are weeks in hand to do something about it rather than a fortnight.
Thirteen months, in one picture
A trough you'd never see coming month by month
Every month here is survivable on its own. Read them in sequence and two of them fall through the floor — because a tax bill and a deposit happen to land back to back, and the recovery takes a quarter.
This is the whole argument for a forecast. Not that any single month is alarming, but that the shape only exists across them.
2 months in the middle of the window end below the $3,000 floor, and then it recovers. A month-to-month budget never shows you this, because every individual month looks survivable.
And the working
Every figure can show where it came from
A forecast you can't interrogate is a guess with better typography. Each month's closing balance is what it opened on, plus what came in, less what went out — and all of it is on the page.
| Flow | Aug 2026now | Sep 2026 | Oct 2026 | Nov 2026 | Dec 2026 | Jan 2027 | Feb 2027 |
|---|---|---|---|---|---|---|---|
| Income | |||||||
| Paycheck | $6,450 | $4,300 | $4,300 | $4,300 | $4,300 | $4,300 | $6,450 |
| Contract work | — | $1,200 | $1,200 | $1,200 | $1,200 | — | — |
| Total in | $6,450 | $5,500 | $5,500 | $5,500 | $5,500 | $4,300 | $6,450 |
| Planned expenses | |||||||
| Rent | $1,850 | $1,850 | $1,850 | $1,850 | $1,850 | $1,850 | $1,850 |
| Groceries | $620 | $620 | $620 | $620 | $620 | $620 | $620 |
| Car insurance | $480 | — | — | $480 | — | — | $480 |
| Savings transfer | $1,200 | $500 | $500 | $500 | $500 | $500 | $1,200 |
| Irregular | Tax bill$5,400 | House deposit$14,000 | |||||
| Total out | $4,150 | $8,370 | $16,970 | $3,450 | $2,970 | $2,970 | $4,150 |
| Baseline | $15,026.93 | $12,156.93 | $686.93 | $2,736.93 | $5,266.93 | $6,596.93 | $8,896.93 |
Money in is green; money out is plain ink, because a planned expense is routine. Red is kept for the one thing that is actually wrong — and it never travels alone, so the months below the floor also carry the stripe and the warning glyph.
Before you commit to anything
Ask what if, and watch the line move
Quick-cast draws a second line on the same chart. Put a couple of hundred aside every month, switch off the thing you're not sure you need, price a bill at three quarters of what it is, skip the holiday in March. The answer redraws as you go — and the forecast underneath doesn't move while you're asking.
It will also tell you the figure you'd otherwise be guessing at: the smallest amount a month that keeps every month above your floor.
Try it
A slider either way, and a switch beside every flow you have. Nothing is written down while you're asking, so there's no version of this you have to undo.
Keep it
Give an answer a name — no holiday, cheaper insurance — and it's saved with what it does to your runway, ready to load again or compare against the next one.
Mean it
When it's the one you want, apply it. The flow takes the figure you were trying on, or a monthly amount becomes a cash flow of its own under a name you choose.
Getting started
- 01
Record what you hold
Each account and its current balance. Two minutes, and it's the only part you repeat — usually once a month, when a statement lands.
- 02
Describe what moves
Income and expenses with their real cadence: monthly, fortnightly, quarterly, annual, or once on a date. Both directions.
- 03
Read your runway
Thirteen months of closing balances, the months that fall through your floor, and the one number that says how long you're clear for.
There is no import, no bank connection and no setup weekend. The walkthrough asks for your balances and your two or three biggest flows, and you have a forecast worth reading before you've entered everything.
Built around how money actually arrives
One number, on the way in
How many months your reserves hold at the rate money is actually moving, and the month they stop. Everything else on the page is the working behind it — but you can close the tab after the first line.
A floor you set, not a zero
Running out isn't the thing you want to be warned about; getting uncomfortably close is. Tell Glideline the lowest balance you're content to see and it measures every month against that, not against nought.
Irregular money, counted properly
A quarterly insurance bill, an annual renewal, a fortnightly paycheck that lands three times in some months. Glideline counts each in its own cadence rather than smearing it into a monthly average, because the average is exactly what hides the bad month.
A date passing isn't proof
A bill due on the 3rd may not be pulled until the 20th, so Glideline keeps expecting it until you tick it off. This month's list is a checklist: tick what has moved, record what the accounts now hold, and the forecast starts from the truth again.
Change one figure, see the whole year move
Rent going up in March, a contract ending in August, one month where the car needs work. Enter it once with its real dates and the thirteen months redraw around it.
Try it before you mean it
Quick-cast is a second line on the chart: put $200 a month aside, switch off the gym, price the insurance at three quarters. Nothing is saved while you're asking — the forecast underneath doesn't move until you say so. When an answer is worth keeping, name it and it's there next time.
Make the answer real in one click
When a what-if is the one you want, apply it. The cash flow takes the figure you were trying on, or a monthly amount you dragged to becomes a cash flow of its own with a name you give it. The question stops being a question.
Your budget app already knows what happened
Connect YNAB, read-only, and match a transaction to what the forecast planned for it. One withdrawal can settle three planned transfers; a $450 standing order that came out at $425 ticks off the plan and moves the balance by what actually moved. Glideline never writes to your budget.
Your figures, in a file you can keep
Everything you've recorded exports as readable JSON — accounts, balances, cash flows, exceptions — and pastes back in. No lock-in, no export request, no waiting on anybody to send you your own data.
What Glideline isn't
- Not a budgeting app. It doesn't categorise spending or tell you where the money went. If that's the question, Glideline is the wrong tool and won't pretend otherwise.
- Not connected to your bank. No banking credentials, no aggregator, no automatic import. You can link YNAB read-only if you keep one — that reads transactions you then match by hand, and Glideline never writes to it. Balances are still yours to record.
- Not advice. It does arithmetic on figures you gave it. What to do about the result is yours.
- Not finished. It is being built in the open and used daily by the person building it. Early access means early.
Questions worth asking
Does Glideline connect to my bank?
No. There are no banking credentials in Glideline and no aggregator in the middle — you record balances yourself, which is a minute of typing when a statement lands. If you already keep YNAB, you can link it read-only: Glideline reads the transactions from a budget you pick so you can match them to what the forecast expected. It never writes to your budget, and it stays optional — everything works without it.
What does quick-cast actually change?
Nothing, until you say so. It draws a second line on the same chart: a monthly amount put aside or spent, a flow switched off, a bill priced differently. The forecast underneath doesn't move. If an answer is worth keeping you can name it and come back to it, and if it's the one you want, one click makes it real — the cash flow takes the figure, or the monthly amount becomes a cash flow with the name you give it.
Can I get my data out?
Yes, and without asking. Everything you have recorded exports as readable JSON — accounts, every balance you have logged, cash flows with their exceptions and what you have ticked off — and the same page takes it back in. It is how you would move to another machine, keep a copy, or leave.
How is this different from a budgeting app?
A budget is about the month you're in: what's left in each category, whether you're overspending now. Glideline is about the months you aren't in yet. It doesn't categorise a single transaction — it answers one question, which is how long what you have lasts against what's coming.
How is it different from a spreadsheet?
Honestly: a spreadsheet can do this, and if yours works, keep it. Glideline is the version that doesn't break when you edit it — cadences that understand months of different lengths, a floor applied consistently, and a projection that starts from today's balance every time you open it rather than from whenever you last dragged the formula down.
What if a bill doesn't come out when it's due?
It goes on expecting it. A date passing is no evidence that money moved, so Glideline keeps counting a landing until you tick it off in This month. That's also why the forecast can't quietly drift out of step with your actual balance.
How far ahead does it look?
Thirteen months — this one and a year of them. Far enough for an annual bill to show up where it lands, and near enough that the figures still mean something.
Is there a password?
No. Signing in sends a link to your email address and following it signs you in. There's no password to choose, forget, reuse or leak.
What will it cost?
That isn't settled yet, and I'd rather say so than name a number I might change. Everyone on the early access list hears the answer before anyone is asked to pay anything.
Find out how long you're clear for
Glideline isn't open to everyone yet. Leave an address and you'll get one email the day it is.
One email when Glideline opens up, and nothing else — no newsletter, no drip campaign. Unsubscribing is a reply.