MoneyCrunchLab
25 free calculators - your numbers never leave your browser
11 followers
25 free calculators - your numbers never leave your browser
11 followers
Free interactive calculators for mortgages, debt payoff, savings, and retirement. Every tool runs entirely in your browser (your numbers never leave it), states its assumptions next to the results, and can be embedded on any website with one line of HTML.
Hi Product Hunt 👋
I built MoneyCrunchLab after noticing that most financial calculators online are either ad-walled quiz funnels or worked examples with someone else's numbers.
So I made 25 interactive calculators (mortgages, debt payoff, savings, retirement) with a few stubborn design constraints:
• Everything computes in your browser — the numbers you type never leave it. No sign-up, no account.
• Every calculator states its assumptions next to the results, and shows the losing side of a trade-off when there is one (rent-vs-buy will happily tell you renting wins).
• Each tool can be embedded on any site with one line of HTML, free, with no ads inside the widget.
• The math is verified against closed-form financial formulas before publication.
If you find a number that looks wrong, tell me — I'll show the math or fix it. Happy to answer anything!
Love that everything runs client-side, the privacy angle is a nice differentiator. One thing that would help a lot: let me save a scenario with a shareable link or short code so I can send my partner my exact mortgage numbers without them retyping everything.
Thanks Mesut! Good news — that’s already in: the URL updates as you type (each input syncs to a query param), so you can copy the address bar mid-calculation and send it. Your partner opens your exact numbers, and nothing is stored server-side. Fair point that it’s invisible though — a proper “Copy link to this scenario” button just went on the list. 🙏@mesut31176
@mesut31176 Update: the "Copy link with your numbers" button is now live on all 25 calculators — shipped the same day. Thanks again for the nudge!
Showing the assumptions next to results is a really nice touch, way more honest than most calculators. One idea: let me save a scenario with my own labels so I can compare "rent longer vs buy now" or "pay extra on card A vs card B" side by side without retyping everything. That would make the embed on my blog way more useful too.
@nurayzbilgtes5 Thanks Nuray! Two existing things get you close: every calculator syncs your inputs to the URL as you type (plus a "Copy link with your numbers" button), so you can keep two tabs open — "rent longer" vs "buy now" — and flip between them or send both links. And embeds accept custom defaults via query params (moneycrunchlab.com/embeds). But you're right that named scenarios compared side by side on one screen is the real feature — it's going on the list. Thanks for the push!
Tried the mortgage calculator and loved that it shows every assumption right next to the numbers. The one-line embed is a nice touch too.
@dne32001344779 Thanks Döne! Showing the assumptions is the founding principle here — a number without its assumptions is just an opinion with digits. Glad the one-line embed looks useful too; it takes custom defaults via query params if you ever want it pre-set for your audience.
Love that every calculator shows its assumptions right next to the results, way more useful than the black-box tools I've tried before.
@aynurhw Thanks Aynur — black-box calculators were exactly the annoyance that started this project. If you ever hit an assumption you'd want adjustable that isn't, tell me and I'll look at adding it.