Unkillable Tools / Calculator / A calculator widget without the subscription
Every major calculator widget builder charges monthly and meters your views. This page explains exactly what you're renting, and what the alternative looks like.
A working shipping calculator, served from this page with no widget service involved.
Change the rates, the labels and the maths to match your business, then export it as a single HTML file you paste into your site. Free, no account, and it keeps working whatever happens to us.
Open the builderIt is not buying compute. A calculator is a few dozen lines of arithmetic that runs on the visitor's device in under a millisecond, and serving it costs fractions of a cent.
What the fee buys is availability. The vendor holds the widget on their infrastructure and serves it on request, which means the ability to stop serving it is the leverage that makes the subscription work. The listed plans make this explicit by pricing in monthly impressions — 500 on a typical free tier, rising into the tens of thousands on paid ones.
The consequence is that the failure mode is tied to your success. Your calculator is most likely to break on the day your page does best, which is precisely the day you needed it.
Once the calculator is a block of HTML on your own server, most of the vendor relationship simply stops existing. There is no plan, no quota, no renewal, no dashboard, no account to lose access to, and no migration project if the vendor is acquired.
There are honest trade-offs. You don't get a hosted analytics dashboard for widget interactions, and you don't get server-side storage of submissions — lead capture posts to your own endpoint instead. For most businesses those are things they already have elsewhere, or never used.
At the cheapest common paid tier of roughly $5 a month, ten years is about $600. At a mid tier of $30, it's $3,600. A one-time $29 licence is $29 in year one and $0 in year ten.
More importantly, the tenth year doesn't depend on the vendor still existing, still offering that plan, or still honouring that price. Software categories with no marginal cost tend toward subscription because subscription is more profitable, not because the cost structure demands it.
The free tier puts a small credit line under the calculator. That's the catch, and it's how people find the tool. $29 once removes it.
Save the project file when you build it. Reopen it here any time, change what you like and re-export. You can also edit the exported HTML directly.
Open your browser's network tab on a page with an exported calculator. You'll see one request: the page itself. You can also read the exported file — it's human-readable and about 21 KB.
Everything already exported keeps working, and everything already exported is the whole product. That's not a reassurance, it's the architecture.
Hosted calculator builders charge $5–$115 a month and stop rendering when you exceed your monthly impressions. This one exports a file that runs on your own site and cannot be switched off.
Build one free