Lifetime vs subscription calculator

How it works

The calculator adds up what you would have paid after using the product for a number of months, for each option:

• Lifetime: the one-time price, plus your extra running cost per month times the months.
• Monthly plan: the monthly price times the months, plus any extra running cost on top of the subscription.
• Yearly plan: the yearly price times the number of years you have started (it is paid at the beginning of each year), plus the same extra running cost.

The break-even month is the first month from which the lifetime total stays at or below the subscription total. With a yearly plan and a running cost on the lifetime side, lifetime can pull ahead, fall behind again before the next yearly payment, and then stay ahead, so the calculator waits for the point after which it never falls behind. The search runs up to 100 years, and if lifetime never catches up, for example because its running costs are as high as the subscription, the result says so. The chart plots the same totals month by month, the dashed line marks your expected period, and the table repeats the numbers for screen readers and for anyone who prefers them.

The extra running cost fields exist for tools where you bring your own AI. If a lifetime tool needs your own API key, the key’s usage bills are part of its cost, while a subscription may bundle AI credits.

What the calculator leaves out: tax, discounts, price rises, currency conversion, resale value and the value of support or updates. Apart from the prefilled Fyslide price, which you can change, it uses only the numbers you enter and makes no claim about any real product.

How to use the result

Be honest about the months. The break-even month only matters if you will actually use the product that long. Try a pessimistic number as well as an optimistic one: if lifetime wins only in the optimistic case, the subscription is the safer pick.

Remember what a lifetime price does not guarantee. “Lifetime” usually means the life of the product, or of the vendor’s willingness to support it, not your lifetime. A vendor may stop releasing updates, change what the license covers, or shut down features that need their servers. A subscription usually costs more over a long time, but it can pay for continuing development, and you can stop paying when you stop needing the tool.

Before you pay for a lifetime license, read what it includes, whether updates are covered and for how long, how many computers it works on, and what the refund policy says. Ask whether the software still works if the company disappears, for instance if it runs locally. None of these questions shows up in a break-even number, but each can matter more than the price.

For a longer treatment, see lifetime license vs subscription, and for one way to run the AI at no per-use cost, writing slideshow text locally with Ollama.