How the Subscription Leak Calculator works
Updated November 2026
What a subscription leak is
A subscription leak is the total your repeating charges take from you in a year. Each charge feels small on its own: 16 dollars here, 12 dollars there. Added up over 12 months, and set beside the yearly charges you barely notice, the small charges become a real number, and that number is the leak.
The yearly math, in plain words
Every row becomes a yearly cost first. A monthly charge is multiplied by 12, because it lands 12 times a year. A yearly charge already is a yearly cost. The calculator then adds the rows. That sum is your yearly leak. Divide it by 12 and you get the average month, which is how the leak feels against a monthly budget. The biggest leak is simply the row with the highest yearly cost, which is often not the row with the highest sticker price: a 16 dollar monthly charge costs 192 dollars a year, more than a 120 dollar yearly charge.
The 10-year figure, in plain words
The second number asks what one year of that leak could become. Picture taking the yearly amount and investing it at the end of each year, for 10 years, at a steady return you choose. That is a standard piece of finance arithmetic called the future value of a yearly investment: the yearly amount times ((1 + r) to the power 10, minus 1), divided by r, where r is the return as a decimal. At a 0 percent return, there is no growth and the figure is exactly 10 times the yearly leak. The page starts at 7 percent. That rate is an assumption for the math, not a promise or a forecast: real returns move up and down, and the guide and the FAQ both say so because it matters.
A worked example
Take the rows this calculator opens with. A video streaming charge of $16 a month costs $192 a year. Music at $12 a month costs $144 a year. Cloud storage at $120 a year costs $120 a year. A news app at $8 a month costs $96 a year. Add them up: the yearly leak is $552, which is $46 a month. The biggest leak is the video streaming charge, at $192 a year, even though the storage charge has the bigger sticker price. Invest $552 at the end of each year for 10 years at 7 percent and it grows to $7,626.68. That is the whole page in one example, and it is the example the calculator is checked against.
Finding your own charges
Most people miss rows, not math. Check the places charges hide: your card and bank statements for the last two months, the subscriptions page in your phone's app store, your PayPal or similar payment account, and your email for renewal receipts. Yearly charges are the easiest to forget, because they land once and stay quiet for 12 months. If a charge bills weekly or every few months, add its yearly total as one yearly row.
What to do with the number
The yearly leak is a snapshot, not a verdict on your choices. Some subscriptions earn their keep. The useful question is which ones you would not buy again today, at the yearly price this page shows, if they asked you fresh. Start with the biggest leak, because that is where one decision saves the most.
What this page leaves out
It does not score your subscriptions for waste, keep renewal dates, or track you over time, and the free page stops at 10 rows. The paid Subscription Tracker Spreadsheet audits 25 rows with waste scores and rankings. This page also treats the return rate as steady, which real investing never is, and it works in the dollars you type today, with no adjustment for price rises.
Sources
- The 10-year figure uses the standard future value of an ordinary annuity formula, the textbook arithmetic for a fixed amount invested at the end of each year: amount times ((1 + r) to the power 10, minus 1), divided by r.
- Product facts and prices for the Subscription Tracker Spreadsheet, the Essential Money Toolkit and the 2027 Money Reset are from the KOLLAZ product catalog, checked 2026-11-10.
Educational information only, not financial advice. Consider a qualified professional for decisions about your specific situation.