About ModelMath
A free tool for developers who need to know what their AI is actually going to cost.
Why This Exists
Every time I started a new AI project, I found myself in the same situation: juggling provider pricing pages, doing back-of-the-envelope math on tokens, and trying to figure out whether context caching actually made sense for my workload. The tools to do this properly either didn’t exist, cost money, or required signing up for something.
ModelMath started as a spreadsheet. Then it became a small internal tool. Then it became this — a free, public calculator that pulls live pricing from OpenRouter and lets you model your actual usage before you write a single line of code.
The goal is simple: no surprises on your bill. Plan before you scale.
Who Built It
I’m Georgy Malanichev, the founder of Character Development— a small product studio that builds tools for developers and technical teams.
I work with AI APIs daily — building products, prototyping ideas, and helping teams integrate LLMs into their workflows. ModelMath is the tool I wished existed when I started. It’s built from direct experience with the friction of LLM cost planning at real production scale.
What the Data Covers
ModelMath tracks 200+ models across every major provider. Pricing data is sourced hourly from OpenRouter — the most comprehensive aggregator of LLM API pricing available. Intelligence benchmarks (reasoning, coding, math) come from Artificial Analysis, who run independent evaluations across standardised benchmarks.
The calculator models input/output token ratios, context caching discounts, and usage frequency to give you a realistic monthly cost estimate — not a theoretical one. You can read the full methodology on the Methodology page.
It’s Free. No Catch.
ModelMath is free to use, with no account required. There’s no freemium tier, no rate limiting, and no data collection beyond standard analytics. The pricing data is fetched directly from provider APIs and displayed as-is.
Prices shown may differ slightly from what you’re invoiced — always verify against your provider’s official pricing page before committing to production spend. ModelMath is a planning tool, not a billing system.
Get in Touch
Bug reports, missing models, data corrections, or just a question — reach out at modelmath@chrctr.dev.
Feature requests are welcome. I can’t promise a timeline, but I do read everything.