230+ Calculators & Converters

CalcTools is a free all in one calculator app for Android: 230+ calculators and a full unit converter in one simple app. Every tool shows the formula, worked examples and sources, so you know exactly how the answer was found.

MONEY & FINANCE
• Loan and EMI calculator, mortgage and credit card payoff calculators
• Debt snowball vs avalanche planner
• Compound interest, savings goal, retirement, inflation and ROI
• Tip, discount, sales tax, unit price and hourly-to-salary

HEALTH & FITNESS
• BMI, body fat, calorie and macro calculators
• Due date, ovulation, water intake, sleep and heart-rate zones
• Blood pressure, blood sugar and cholesterol category checkers

MATHS & STUDY
• Percentage, percent error, fraction, ratio and average
• Quadratic equation solver with discriminant and vertex
• GCF/LCM, scientific notation, GPA and final grade

DATES, CARS & TECH
• Age, date difference and add-days calculators, Hijri date converter
• Fuel cost, fuel economy, engine displacement, tyre size and gear speed
• Uptime/SLA, download time, backup storage and AI API cost

UNIT CONVERTERS
A complete unit converter app: length, weight, temperature, volume, area, speed, pressure, power, energy, data and more, with metric and imperial units and ready-made conversion tables.

WHY CALCTOOLS
• Calculations run on your phone. Your numbers are never uploaded.
• Clear explanations, worked examples and common mistakes for every tool
• Light, fast and free: one calculator app instead of ten

Results are estimates for general information. For medical, financial or legal decisions, check with a qualified professional.

NOT A GOVERNMENT APP
CalcTools is an independent app and is not affiliated with, endorsed by or acting for any government agency. Where a calculator uses official figures (for example IRS tax tables or SSA wage limits), the government source is linked on that page.