Yearly plan or monthly? Find the break-even.
The yearly price looks like a discount until you cancel in month seven. This shows the exact month the annual plan starts winning, so you can decide with a number instead of a feeling.
Your numbers
Result
Break-even
0 months
Part of Money Kit, a free appSave your details once and all 8 tools fill themselves in. Installs to your phone, works offline, nothing leaves your device.Open The break-even month
Divide the yearly price by the monthly price. $99.99 divided by $12.99 is 7.7, so the annual plan wins if you keep it 8 months or more. Under that, you paid for months you did not use. Most annual plans break even between month 8 and month 10, which is exactly the window where people stop using things.
When annual still loses at 12 months
Price increases. An annual plan locks a rate, but it also locks you in through a rate increase you might have used as a reason to leave. And "annual" plans on the App Store auto-renew at the then-current price, so the second year is not the deal the first year was. Check the renewal price before the renewal date, not after.
A simple rule
Go monthly for the first two or three months of anything new. If you are still using it at month three, switch to annual, you have proven the habit. Switching mid-cycle usually gives you credit for the unused monthly time on the App Store.
Assumes the monthly plan can be cancelled any month with no penalty, and ignores taxes and intro pricing. Not financial advice.