Turning seven billing cycles into one monthly number
Every item is converted through the number of charges it produces in a year: weekly 52, every 2 weeks 26, every 4 weeks 13, monthly 12, quarterly 4, half-yearly 2, yearly 1. Yearly cost is amount × charges; the monthly figure is that divided by 12. Nothing is estimated — a quarterly 30 is exactly 120 a year and 10 a month.
The four-week cycle is the one that catches people out. It is 13 charges a year, not 12, so a 9.99 “every 4 weeks” plan costs 129.87 a year while a 9.99 monthly plan costs 119.88 — an extra charge, roughly 8.3% more, for what looks like the same price. UK mobile and some gaming subscriptions are billed this way deliberately.
Only active items and trials count towards the totals — a trial will bill, so leaving it out would understate what is coming. Paused and cancelled items stay in the list for reference but contribute nothing, and the “what if I cancel these” checkboxes let you take items out of the total temporarily without deleting them.
How the next billing date is found
You give one billing date you know — any one, past or future — and it becomes the immovable anchor of the series. The tool steps the cycle forward from that anchor until it passes today, so entering a date from two years ago is normal and produces the right answer rather than an error.
Short months clamp rather than drift. A 31st anchor bills on 28 February — 29 in a leap year — and then returns to the 31st in March, exactly as card billing works. A tool that instead moved the anchor to the 28th would shift every future date for the rest of the subscription’s life, which is why the anchor is never rewritten.
A free trial anchors differently: the first charge is the day the trial ends, so that date — not the day you signed up — drives the series. Enter the trial end date and the tool treats the trial as a subscription that has not started billing yet, counts it in the totals, and puts its first charge in the calendar.
Cancellation deadlines, not just renewal dates
Knowing the renewal date is not enough when the service needs notice. Enter how many days ahead you must cancel and the tool subtracts that from the renewal to give a cancellation D-day — the date after which you are committed to another cycle. A yearly plan with 30 days’ notice must be cancelled 11 months after you started it, not 12.
Lead time accepts up to 90 days, which covers the annual gym and insurance-style contracts where the notice period is the actual trap. For a free trial the deadline is measured from the trial end, so a 3-day notice on a 7-day trial gives you four days to decide.
Both dates go into the .ics export as separate entries, so your calendar shows “cancel by” before it shows “charged”. That ordering is the point: a reminder that arrives on the billing day is a receipt, not a warning.
Yearly vs monthly billing: what the switch is worth
The saving is only calculated where you enter an actual yearly price. Nothing is inferred from a “usually two months free” rule of thumb, because the discount genuinely varies: some services give 2 months, some 20%, some nothing at all, and a made-up figure in a savings total is worse than a blank.
The arithmetic is monthly × 12 − yearly. A 9.99 monthly plan sold at 99.90 a year saves 19.98, or 16.7%. Before switching, weigh two things the number cannot: a yearly commitment removes the option to leave in month three, and yearly plans are where the notice-period cancellation trap above lives.
The preset list also records where the same plan costs more bought through an app store than on the web, which is the other silent premium in this category. Prices in the presets were verified on the date shown next to them; they are starting values to save typing, not a live price feed.
Mixed currencies, and why a total can go missing
Each item keeps the currency it is actually billed in. This matters more than it sounds: ChatGPT Plus and Claude Pro are charged in dollars to Korean cards, so a list that forced everything into won would be wrong on the two items most likely to be there. Totals are converted with European Central Bank reference rates and the rate date is always shown.
If a rate cannot be loaded — offline, or a currency the ECB does not publish — the tool shows per-currency subtotals and leaves the grand total blank rather than guessing. A single-currency list needs no rate at all and keeps working completely offline, so the failure costs exactly the totals that genuinely needed a conversion.
Card issuers add a foreign transaction fee of roughly 1–3% on top of the rate you see here, so a foreign-currency subscription costs slightly more on your statement than the converted figure. The rate itself is a reference mid-rate, not the retail rate your bank applies.
The five- and ten-year totals
With no price-rise assumption, the long totals are simply the yearly figure multiplied out. Enter an expected annual increase and each year is compounded instead: the sum of annual × (1 + rise)^k for k = 0 to n − 1. A 600-a-year habit is 3,000 over five years flat, but 3,315.38 if prices climb 5% a year.
The point of the long horizon is not prediction; it is scale. A 15-a-month subscription reads as pocket change and as 900 over five years, and the second framing is the one that makes an unused item easy to cancel. Streaming and music services have raised prices repeatedly in recent years, so 3–5% is not a pessimistic assumption.
Running a subscription audit
- Start from your card statement, not from memory. The items you forget are exactly the ones worth finding, and they are almost never the ones you would have listed.
- Check for duplicates: a family plan and an individual plan for the same service, cloud storage bought twice on two accounts, a music service bundled inside a mobile plan you also pay for.
- Sort by yearly cost, not monthly. A 129 annual plan hides better than a 12-a-month one, and the categories view shows which group — streaming, AI, commerce, fitness — has grown without you noticing.
- Use the cancel simulation before cancelling anything: untick the candidates and read the new monthly and yearly totals. Seeing the number move is what turns “I should cancel that sometime” into a decision.
- Export the .ics last, so every renewal and cancellation deadline you decided to keep is in your calendar rather than in this browser only.