16 fast, accurate tools for finance, tax, health, dates and unit conversion. Everything runs in your browser — free, private, no sign-up.
Equal payment & equal principal, full amortization schedule
China IIT 2026 brackets, take-home pay with deductions
Body Mass Index with categories & health advice
Length, weight, temperature, area, volume, speed
Days between dates, anniversary share cards
Exact age in years, months & days, next birthday
Simple & compound interest on deposits or loans
Social insurance, housing fund & IIT deductions
Percent of, percent change and ratio modes
Days, weeks and hours between two dates
Sale price and savings from any discount
Rectangle, circle, triangle & more shapes
Random integers in any range, dice roller
Binary, octal, decimal, hex conversions
Appliance wattage × hours × rate = monthly cost
Split any bill evenly among friends
CalcTools is a collection of 16 free online calculators covering the calculations people search for most: mortgage monthly payments, China personal income tax, take-home salary, simple and compound interest, BMI, unit conversion, dates and ages. Every tool is instant, works on mobile and desktop, and requires no registration.
Planning to buy a home? The mortgage calculator compares equal payment and equal principal methods and shows a full amortization schedule. Filing taxes? The income tax calculator applies the 2026 China IIT brackets with special additional deductions. Watching your health? Track your BMI in seconds.
For quick answers also try the unit converter, percentage calculator, interest calculator and age calculator.
Yes. Every tool on CalcTools is completely free with no registration required.
Yes. All calculations run locally in your browser. We never receive, store or transmit anything you type.
Absolutely. The site is fully responsive and works on phones, tablets and desktops.