MonsiTools

MonsiTools is a calculator and workflow builder for founders, freelancers and online sellers who answer the same money questions again and again.

Build: type how an answer is worked out in plain words, such as price - product cost - shipping, and MonsiTools turns each word into a labelled field with units and a live preview. Formulas support brackets, powers, if/else choices and functions like min, max and round. Saved calculators can be shared with a link.

Chain: line up any calculators, your own and 1,262 ready-made ones, into a workflow. Each step can carry in an earlier result, so a job offer turns into monthly take-home pay, or MRR turns into runway and then a valuation, without copying numbers between tabs.

Decide: compare two scenarios side by side, run a sensitivity check on any input, save reusable workspace variables such as MRR or a day rate, and export a whole workflow run as a PDF decision report.

Use it anywhere: a JSON API and an MCP server let Google Sheets, Zapier and AI assistants such as Claude and ChatGPT run MonsiTools calculators directly.

Calculations run in the browser. Every calculator works on a limited plan (15 uses without an account, or 25 a month signed in). Premium costs $5.49 a month and removes the limits.