Most people's estimate of their subscription spending is wrong by a factor of two, and always in the same direction. The reason is arithmetic, not denial: annual plans get left out.
The short answer
Convert everything to the same period before you add it up. Divide annual plans by 12, multiply weekly ones by 52 then divide by 12, and include the ones billed to accounts you don't check. Then look at the yearly figure — it's the one that changes behaviour.
Step 1: normalise the billing cycles
You can't add £11.99/month to £119/year and get anything meaningful. Put everything on the same footing first:
| Billed | To get monthly | Example |
|---|---|---|
| Weekly | × 52 ÷ 12 | £2.99/wk → £12.96/mo |
| Monthly | as is | £11.99/mo → £11.99/mo |
| Quarterly | ÷ 3 | £30/qtr → £10.00/mo |
| Yearly | ÷ 12 | £119/yr → £9.92/mo |
Weekly is the one people get wrong. Multiplying by four undercounts by roughly 8% — there are 4.33 weeks in an average month, not 4.
Step 2: stop undercounting
Four things that reliably make the total look smaller than it is:
- Leaving out annual plans because they don't feel like monthly costs. They are; they're just prepaid.
- Forgetting the small ones. Four £2.99 subscriptions is £143 a year. The small ones are individually ignorable and collectively significant — this is exactly how they survive.
- Ignoring other people's cards. Household subscriptions billed to a partner's card still come out of the same money.
- Counting the promotional price. If you're on a discounted first year, your real ongoing cost is the renewal price, not what you're paying now.
Step 3: look at the yearly number
Monthly figures are psychologically easy to dismiss — £47 a month sounds like nothing much. £564 a year sounds like a holiday. It's the same money; the yearly framing is just harder to wave away, which is precisely why it's the useful one.
Do both: monthly for budgeting, yearly for deciding.
A note on multiple currencies
If you pay for things in more than one currency, adding them into a single number requires an exchange rate — and the rate moves, so the total is an estimate that goes stale. Some trackers convert; TrialBell deliberately doesn't, and shows a separate total per currency instead. We go through the trade-off in tracking subscriptions in multiple currencies.
Step 4: do something with the number
The point isn't the figure, it's the sort that follows it. Rank everything by yearly cost and work down from the top — the ranking usually surprises people, because the most expensive line is rarely the one they'd have guessed. Our guide on deciding which subscriptions to cancel picks up from there.
TrialBell shows monthly and yearly totals from what you've entered, so the number updates itself as you add, change or cancel things — deliberately just the numbers, not a budgeting dashboard.
One list, kept current
TrialBell tracks every trial, subscription and bill on your iPhone, works out the cancel-by date, and reminds you before each renewal. No bank connection, no account. Free for 3 subscriptions; Pro is a one-time $19.99.
Coming soon to theApp StoreFrequently asked
How do I work out my monthly subscription cost including annual plans?
Divide each annual plan by 12 and add it to your monthly ones. For weekly subscriptions, multiply by 52 and divide by 12 — multiplying by 4 undercounts by about 8%, because an average month is 4.33 weeks.
Why is my real subscription spending higher than I thought?
Usually four reasons: annual plans left out of the mental total, several small subscriptions that are individually ignorable, subscriptions billed to a partner's card, and counting a promotional price rather than the renewal price.
Should I look at the monthly or yearly total?
Both, for different jobs. Monthly is what you budget against; yearly is what makes you act. The same £47 a month reads very differently as £564 a year.
Written by the TrialBell team and updated 29 July 2026. Where this guide describes another app, the detail comes from that app's public App Store listing on the date shown.