Online Tool Store
Subscription Cost Tracker
Add up subscriptions billed weekly to yearly with the conversion done properly, see the cost per use of each, and export a CSV. Stays in your browser.
🔒 This tool runs entirely in your browser. Your files are never uploaded to a server.
Cosmetic only — no rates are fetched.
Totals
| Subscription | Price | Billed | Uses a month | Per year | Per use | Remove |
|---|
Where your list is kept. In this browser's local storage, on this device only. There is no account and nothing is uploaded, which also means it is not backed up and will not follow you to another browser — download the CSV if you want a copy. It also cannot convert between currencies, since that would need live rates; keep one currency per list for the totals to mean anything.
How to use it
- Replace the sample rows with your own, or add new ones.
- Set how each one is billed — weekly through to yearly.
- Put in roughly how often you use each, to get a cost per use.
- Download the CSV if you want a copy outside the browser.
A week is not a quarter of a month
This is the arithmetic almost every subscription total gets wrong, and it always errs the same way — downwards. There are not four weeks in a month:
365.25 ÷ 7 = 52.178571 weeks a year
÷ 12 = 4.348214 weeks a month
£10 a week correct → £43.48 a month, £521.79 a year
× 4 → £40.00 a month, £480.00 a year
the gap → £41.79 a year, 8% short
Fortnightly is the same trap wearing a different hat: twenty-six payments a year, not twenty-four, so treating "every two weeks" as "twice a month" loses the same 8%. If your list contains anything billed weekly or fortnightly, the tool shows you what the shortcut would have said — the sample list is short by £18.80 a year.
Why the yearly figure comes first
Costs on different billing cycles cannot be added directly. So every price is converted to a yearly amount, the yearly amounts are summed, and the monthly and daily figures are divided out of that total. Converting each item to a monthly figure first and adding those instead accumulates a rounding error per row, and it makes the weekly mistake above almost inevitable.
It also happens to be the more useful number. A £12.99 monthly service does not feel like much; £155.88 a year does, and that is the figure worth comparing against what you would otherwise do with the money.
Cost per use changes the conversation
Gym £34.50 a month, used 6 times → £5.75 a visit
Music £10.99 a month, used 25 times → £0.44 a day
Same order of magnitude on the invoice, an order of magnitude apart in value. Per-use cost is the number that tells you which one to keep, and the tool names the worst offender rather than leaving you to scan the column. Anything left at zero uses is totalled separately, because that is where the easy savings usually are.
What it deliberately does not do
It does not connect to your bank, read your email, or fetch exchange rates — it has no server side at all. That is the reason it is free, instant and private, and it is also its limitation: a bank-connected app can find the subscriptions you have forgotten about, which is the hardest part of the problem. This tool can only add up what you tell it. Your list is kept in the browser's local storage on the one device, so treat the CSV download as your backup.
FAQ
Why is a weekly subscription not four times the monthly figure?
Because a month is longer than four weeks. There are 52.18 weeks in a year, so 4.35 in an average month. A £10 weekly subscription is £43.48 a month and £521.79 a year — the ×4 shortcut gives £40 and £480, understating it by 8%.
Why does it show the yearly figure first?
Because the yearly figure is the one that survives mixing billing periods. Monthly, quarterly and weekly costs cannot be added together directly, so everything is converted to a yearly amount first and the monthly number is derived from that. Doing it the other way round is where the rounding errors creep in.
What is cost per use for?
Turning an abstract monthly charge into something you can judge. A £12 service used twice a month is £6 a viewing; the same £12 used twenty times is 60p. It is usually far more persuasive than the headline price when you are deciding what to cancel, and it is why the column is there rather than buried.
Where is my list stored?
In your browser's local storage, on that device only. There is no account and nothing is uploaded — which also means there is no backup and it will not appear on your phone. Download the CSV if you want a copy that outlives the browser.
Can it handle subscriptions in different currencies?
It will display any symbol you like, but it does not convert. Converting would need live exchange rates, and this tool fetches nothing at all. Keep one currency per list, or the totals will be adding pounds to dollars.
Does it know when my subscriptions renew?
No. It has no connection to your bank, your email or any provider, so it only knows what you type. That is the trade for it being free and private — a bank-connected app can find subscriptions you have forgotten, and this cannot.
How we compare
| Feature | Online Tool Store | A spreadsheet | Bank-connected apps |
|---|---|---|---|
| Correct weekly and fortnightly conversion | ✓ | Only if you wrote it correctly | ✓ |
| Cost per use, and the worst offender named | ✓ | Another column to build | ✗ |
| Nothing uploaded, no account | ✓ | Depends where it lives | ✗ |
| Ready in seconds, no setup | ✓ | ✗ | ✗ |
| CSV export | ✓ | ✓ | Sometimes |
| Finds subscriptions you forgot about | ✗ | ✗ | ✓ |
| Syncs between your devices | ✗ | ✓ | ✓ |
Faster than building a spreadsheet and it gets the weekly arithmetic right, with a cost-per-use column that actually helps you decide. It cannot see your bank, so it will not find the subscription you forgot — if that is your problem rather than the maths, a connected app is the tool that solves it.