# CodeASystem Calculators

- **URL:** https://codeasystem.com/calculators/
- **Markdown index:** https://codeasystem.com/calculators/index.md
- **Total calculators:** 173

173 free online calculators for money, health, math, dates, building, shipping code and running systems. Every calculator documents its inputs, outputs, formula, assumptions and limits, and ships a Markdown version of its page at the same URL with a `.md` suffix.

## Categories
- [Finance](https://codeasystem.com/calculators/finance/index.md); 18 calculators. Loans, mortgages, savings, investing and debt
- [Business & SaaS](https://codeasystem.com/calculators/business/index.md); 10 calculators. Margins, pricing, SaaS metrics and break-even analysis
- [Salary & Payroll](https://codeasystem.com/calculators/salary/index.md); 5 calculators. Pay conversion, overtime, raises and freelance rates
- [Health](https://codeasystem.com/calculators/health/index.md); 11 calculators. BMI, calories, body composition and pregnancy dates
- [Fitness & Sports](https://codeasystem.com/calculators/fitness/index.md); 7 calculators. Pace, lifting maxes, heart rate and calorie burn
- [Dates & Time](https://codeasystem.com/calculators/dates/index.md); 5 calculators. Ages, durations, working days and date math
- [Math](https://codeasystem.com/calculators/math/index.md); 9 calculators. Percentages, fractions, ratios and algebra
- [Statistics](https://codeasystem.com/calculators/statistics/index.md); 10 calculators. Averages, spread, probability and regression
- [Geometry](https://codeasystem.com/calculators/geometry/index.md); 9 calculators. Areas, volumes, angles and distances
- [Conversions](https://codeasystem.com/calculators/conversion/index.md); 9 calculators. Length, weight, temperature, data and speed
- [Education](https://codeasystem.com/calculators/education/index.md); 6 calculators. Grades, GPA and study estimates
- [Construction & DIY](https://codeasystem.com/calculators/construction/index.md); 8 calculators. Concrete, paint, tiles, mulch and roof pitch
- [Food & Cooking](https://codeasystem.com/calculators/food/index.md); 5 calculators. Recipe scaling, ratios and kitchen math
- [Everyday](https://codeasystem.com/calculators/everyday/index.md); 8 calculators. Fuel, bills, pets and daily-life math
- [Marketing & Ecommerce](https://codeasystem.com/calculators/marketing/index.md); 8 calculators. Ads, funnels, conversions and store metrics
- [Social Media](https://codeasystem.com/calculators/social/index.md); 4 calculators. Engagement, growth and creator earnings
- [Climate & Environment](https://codeasystem.com/calculators/climate/index.md); 4 calculators. Footprints, emissions and weather comfort
- [Developer & Tech](https://codeasystem.com/calculators/developer/index.md); 37 calculators. Encoding, security, networking, cloud and AI cost tools

Follow a category link to list every calculator in it, then follow an individual calculator link for its complete reference: inputs, outputs, formula/methodology, worked example, assumptions and FAQs.

---
Last updated: 2026-08-23