Free Online Calculators
40 calculators across finance, health, math & education, time & date, and everyday use — all in your browser. No signup; math runs locally in JavaScript.
Finance calculators
Investments, loans, tax, rent, deposits, and GST — tuned for Indian rupees where it matters.
SIP Calculator
Systematic investment plan maturity & returns
🏦EMI Calculator
Loan EMI, interest & amortization
🏠Home Loan + Prepay
EMI with prepayment simulation
📋Income Tax
India FY — new vs old regime
💰FD Calculator
Fixed deposit maturity & interest
🧾GST Calculator
Add or remove GST; CGST/SGST split
🏛️PPF Calculator
Public Provident Fund maturity & yearly table
💵Lumpsum Calculator
One-time investment growth & chart
🏘️HRA Calculator
House rent allowance exemption
🌴Retirement
Corpus, inflation & SIP to goal
📅RD Calculator
Recurring deposit maturity & quarters
💼Salary (CTC → in-hand)
India take-home & regime compare
🏛️NPS Calculator
National Pension Scheme corpus & pension estimate
📊Compound Interest
Growth, EAR, and year-by-year table
💧SWP Calculator
Systematic withdrawal & sustainability
💳Personal Loan EMI
Unsecured loan EMI, fees & amortization
🏡Mortgage (US)
PITI, PMI, taxes & yearly schedule
📉Stock Average / P&L
Average buy price & profit after charges
Health calculators
Screening tools — not medical advice. Consult professionals for diagnosis or meal plans.
BMI Calculator
Body mass index & categories
🔥Calorie / TDEE
Daily calories, BMR, macro example
📏Ideal Weight
Devine, Robinson, Miller, Hamwi + BMI band
📐Body Fat (US Navy)
Tape method body fat percentage
🍼Due Date
EDD from LMP (280-day & Naegele)
💧Water Intake
Daily hydration from weight & activity
🥗Macro Calculator
Protein, carbs & fat for your goal
🌸Period & Ovulation
Cycle estimates & fertile window
❤️Heart Rate Zones
Max HR & training zones
Math & education
Fractions, statistics, percentages, GPA, and a full scientific keypad — homework and desk work without installing software.
Time & date
Age from birthday, span between dates, and clock arithmetic for shifts and travel.
Everyday calculators
Tips, discounts, unit conversion, rent vs buy, and retail markup vs margin — quick mental-load helpers.
Calculator FAQ
Do I need an account?
No. Open a calculator, type your numbers, and see results immediately in your browser.
Are my inputs stored on DoItSwift servers?
Calculations run locally in JavaScript. We do not receive your salary, loan, or health numbers unless a future feature explicitly says otherwise.
What’s included in the 40 calculators?
Finance (SIP, EMI, home loan, personal loan, mortgage, stock average, income tax, FD, GST, PPF, lumpsum, HRA, retirement, RD, salary, NPS, compound interest, SWP), health (BMI, calorie/TDEE, ideal weight, body fat, pregnancy due date, water intake, macros, period & ovulation, heart rate zones), math & education (percentage, scientific, GPA, fraction, statistics), time & date (age, date difference, time math), and everyday tools (tip, discount, units, buy vs rent, markup & margin). Highlights include mortgage (PITI), period tracking estimates, and descriptive statistics with charts.
Are tax and EMI numbers legally binding?
No — they are educational estimates. For tax filing or loan decisions, confirm with a chartered accountant or your bank.
Do calculators work on mobile?
Yes. Use any modern phone browser; layouts stack for small screens.