Calculators that show their working
33 free calculators for money, health and everyday maths. Every one explains the formula behind the answer, works offline once loaded, and never asks you to sign up.
Finance Calculators
Loan payments, EMIs, interest and savings calculators that show the formula behind every result.
- Car Loan Calculator Monthly car payment with trade-in and sales tax handled in the right order.
- Compound Interest Calculator Growth with compounding and monthly deposits, showing interest separately from contributions.
- EMI Calculator Monthly EMI, total interest, and the flat rate your reducing rate really equals.
- Home Loan Eligibility Calculator How much home loan you qualify for, using FOIR and the RBI loan-to-value caps.
- Loan Calculator Monthly payment, total interest and repayment total for any fixed-rate loan.
- Mortgage Calculator Full monthly payment including tax, insurance and HOA — not just principal and interest.
- ROI Calculator Total and annualised return, the only fair way to compare different holding periods.
- Savings Goal Calculator The monthly amount needed to reach a target by a chosen date.
- Simple Interest Calculator Interest on the principal only, compared directly against the compounded equivalent.
Tax & Salary Calculators
Indian income tax, GST, HRA exemption, gratuity and take-home pay, with the slab-by-slab working shown.
- Gratuity Calculator Gratuity under the 1972 Act, with the five-year rule and ₹20 lakh cap applied.
- GST Calculator GST in both directions, with the CGST/SGST/IGST split for your invoice.
- HRA Exemption Calculator HRA exemption under section 10(13A), showing which of the three limits binds.
- Income Tax Calculator (FY 2025-26) Income tax for FY 2025-26 under both regimes, with the slab working shown.
- Take-Home Salary Calculator What a CTC offer really pays monthly, after PF, gratuity provision and tax.
Investment Calculators
SIP, fixed deposit, recurring deposit and PPF returns, using the compounding convention each product actually uses.
- FD Calculator FD maturity with the quarterly compounding Indian banks actually use.
- PPF Calculator PPF maturity over 15 years or longer, with the ₹1.5 lakh cap applied.
- RD Calculator RD maturity with monthly deposits and quarterly compounding handled properly.
- SIP Calculator SIP maturity with optional annual step-up, splitting returns from contributions.
Student Calculators
CGPA and percentage conversion, attendance requirements and the marks you need in a final exam.
- Attendance Calculator Attendance percentage, classes you can still miss, and classes needed to recover.
- CGPA to Percentage Calculator CGPA and percentage conversion, with the multiplier made an explicit choice.
- Exam Marks Calculator Marks needed in the final to hit a target grade — and whether it is reachable.
Health Calculators
BMI, calorie, body composition and hydration calculators using published clinical formulas.
- BMI Calculator Body mass index with WHO category and your healthy weight range.
- BMR Calculator What your body burns at rest and in total, using Mifflin-St Jeor.
- Body Fat Calculator Body fat percentage from tape measurements, plus fat and lean mass.
- Calorie Calculator Daily calorie target for a chosen rate of weight change, plus a macro split.
- Ideal Weight Calculator Four classical ideal weight formulas compared against the healthy BMI range.
- Water Intake Calculator Daily water needs by weight, exercise and climate — including what food supplies.
Everyday Calculators
Percentages, tips, discounts, dates and unit conversions for day-to-day maths.
- Age Calculator Exact age in years, months and days, counted the way the calendar does it.
- Date Difference Calculator Days, weeks, months and working days between any two dates.
- Discount Calculator Real sale price after stacked discounts — which never add up the way they look.
- Percentage Calculator Two numbers in, all three percentage answers out — no mode switching.
- Sales Tax Calculator Adds tax to a price, or correctly extracts it from a tax-inclusive total.
- Tip Calculator Tip and per-person split, with tax kept separate from the tip base.