📒 Budget
Put in what comes in and what goes out, each at its own frequency, and see what is left over a week, a fortnight or a month. Everything is saved on this device only.
Income and expenses
Nothing here yet. Add your income and expenses and the page works out what is left over in each period. A weekly grocery shop, a monthly rent payment and a yearly insurance bill can all go in the way they arrive.
Why use this budget?
A budget in a spreadsheet asks you to convert everything to one frequency before it can add anything up, and that is the step most people abandon: the rent is weekly, the power is monthly, the insurance is yearly, and one of them always has to be wrong. This page takes every bill at the frequency it actually arrives in and does the converting itself, so the only figure you need to know is what the thing costs. It then answers the two questions worth asking — what is left over, and where the money went — and it keeps every number on your own device: there is no account, no sign-up and nothing sent anywhere.
What the research says about budgets
Budgets are old, and the way people behave inside one has been studied closely enough to have names for it:
- The word budget began as a bag. It comes from the Old French bougette, a little leather pouch — a diminutive of bouge, “leather bag” — and the money sense only arrived later, from what the bag held.
- Mental accounting is Richard Thaler’s term for a very human habit: people sort money into separate mental accounts by label, such as rent, groceries or holidays, and then treat a dollar differently depending on which account it sits in. A written budget is, in effect, a deliberate version of something people already do by instinct.
- Payment decoupling is the other finding worth knowing: people are consistently willing to pay more for the same thing with a card than with cash, because paying later and in the abstract hurts less than handing over notes. It is the reason a running total on a screen does not feel the same as a wallet getting thinner.
How does this calculator work?
Each entry is first worked out as a yearly amount, and that is then divided into the period you are viewing. It is the one rule the whole page rests on:
amount in the period = amount × times per year ÷ periods per year
so a weekly amount is × 52, a monthly one × 12, and a year is then divided by 52 for weeks, 26 for fortnights or 12 for months.
- A recurring entry counts in every period from the one containing its start date onwards, so you enter your rent once and it is there in every fortnight after. It is averaged to the period being viewed, which is why a $2,000-a-month rent shows as about $923.08 in a fortnight.
- A one-off entry counts only in the period containing its date — a single purchase, a bond, a vet bill.
- Weekly and fortnightly periods are counted from an anchor date of your choosing (your payday, say), and monthly ones follow the calendar. Change the anchor in settings and the periods move with it; no entry changes.
- The weekly / fortnightly / monthly switch decides what the amounts are per. The arrows beside it walk through actual periods. They are two different things, and using one never changes what you entered.
- Everything is saved in this browser's own storage on this device, and a backup file is how you move it to another one.
Frequently asked questions
Where is my data saved, and who can see it?
In this browser's own storage, on this device, and nowhere else. There is no account, no sync and no server involved, so nobody — including whoever runs this site — can see what you enter. The trade is that the data belongs to the browser: clearing your browsing data, or using a private window, takes it with it. If the browser refuses to store anything at all, the page says so at the top rather than pretending it saved.
Why is a month not four weeks?
Because there are 52 weeks in a year, and 52 ÷ 12 is about 4.33. Treating a month as four weeks leaves out nearly a month of the year, which is why $650 a week shows as $2,816.67 a month here rather than $2,600. Over a year that difference is around $2,600, and it is the reason every amount on the page goes through the yearly figure instead of a shortcut.
What is the difference between the period on screen and the switch?
The switch says what the amounts are per — a week, a fortnight or a month. The arrows and the date beside them move you through actual periods: the fortnight of 28 September, then the one after it. So you can read a weekly budget for the fortnight you were actually paid in, which is the comparison people usually want.
Do I have to convert my bills to one frequency first?
No — that is the point of the page. Each entry keeps the frequency you chose for it: one-off, weekly, fortnightly, monthly, bi-monthly (every 2 months), quarterly, 6 monthly or yearly. Rent can be weekly, power monthly and insurance yearly, and the totals still come out right, because each one is converted on its way into the sum.
What happens to my entries if I delete a category?
They move to that kind's "Other" category — "Other" for expenses, "Other income" for income — and they keep their own names, so nothing is lost and nothing disappears out of the totals. Those two categories cannot be deleted, which is what stops an entry from ever being left without a home.
How do I move all of this to a new phone?
Use Back up my data in settings: it writes a small JSON file you can save to iCloud Drive, email to yourself or drop in a folder. On the new device, Restore from a backup reads that file back. A restore replaces everything, so it asks first and tells you how many entries the file holds and how many are in the budget now.
What does the share button actually send?
The sentence on the result card and a link to this page, and nothing else. The site sends nothing anywhere by itself: the button hands that sentence to your own device’s share sheet, or puts it on your clipboard when the device has no share sheet to offer. What you do with it after that is between you and whichever app you picked.