Free Calculators + AI Math Skills

395 free online calculators across 19 categories: finance, real estate, construction, health, and more. Every tool shows the formula and explains the math step by step.

A calculator for whatever you need to figure out.

Pick the category that fits your problem and we'll show you every calculator in it. From mortgage payments to muscle gain, concrete pours to coconut swallow velocity — every tool shows the formula and explains the math.

Finance & Money Calculators

52 free tools

Health & Medical Calculators

38 free tools

Construction & Home Calculators

35 free tools

Math & Numbers Calculators

30 free tools

Unit Conversion Calculators

25 free tools

Memes Calculators

25 free tools

Fitness & Body Calculators

22 free tools

Science & Engineering Calculators

20 free tools

Business & Startup Calculators

18 free tools

Cooking & Kitchen Calculators

18 free tools

Automotive & Transport Calculators

16 free tools

Real Estate & Property Calculators

15 free tools

Time & Date Calculators

15 free tools

Education & GPA Calculators

14 free tools

Environmental & Energy Calculators

12 free tools

Pregnancy & Baby Calculators

12 free tools

Electronics & Tech Calculators

10 free tools

Travel & Geography Calculators

10 free tools

Pet Care Calculators

8 free tools

Custom build · 5-day delivery

$299

A suite of up to 5 calculators built to your spec

Custom Suite

Don't see what you need? We'll build it for you.

Start a brief

12 collections

Made for the week you're having

Pre-built calc packs for the kind of week you're in. Office survival, late-night group-chat disputes, the existential Tuesdays — pick a pack, share the results, settle the debate.

See all collections

🗓

8 calculators

Office Survival

Math for the part of the week your soul leaves your body

🌹

5 calculators

Dating Delusion Pack

Translate ambiguous texting into pattern-matched honesty

🌀

8 calculators

Internet Culture

Real formulas for the math the internet keeps arguing about

🎬

6 calculators

Cinema Night

Math for the rewatch — settle the bets the movie keeps starting

💬

6 calculators

Group Chat Disputes

For the debate currently consuming your group chat

🌫

6 calculators

Existential Tuesday

When nothing's wrong but everything feels heavy

🧾

5 calculators

The Adulting Audit

The spreadsheet your therapist would build for you

🥂

5 calculators

First-Date Forecast

Before, during, and the post-mortem

🦝

6 calculators

WFH Goblin Mode

From your couch, in pajamas, with the door locked

🌅

5 calculators

Monday Morning Reset

What the week is actually going to cost you

📼

6 calculators

80s & 90s Nostalgia Hour

Memory lane, with formulas

🔍

5 calculators

Everything Is Sus

When the vibes are off and you need numbers to confirm it

Pricing

Free to use. Pay only if you want AI superpowers.

Every calculator on Calc.Cards is free in the browser. The paid tiers turn calculators into AI-ready skill files for Claude Code, ChatGPT, and other LLM workflows.

Tier 1