CheckMatter Tools
Free Online Calculators by Category
Find the right calculator without searching through unrelated pages. Every listed tool has a verified live URL and appears in one primary category.
Finance Calculators
Plan loans, investments, taxes, bills, prices, and everyday money decisions.
EMI Calculator
Estimate loan EMI, total interest, amortization, and prepayment savings.
Open calculatorMortgage & Loan Calculator
Estimate monthly payments and total interest for a mortgage or general loan.
Open calculatorCar Loan Calculator
Calculate a car-loan payment, interest cost, and repayment summary.
Open calculatorGST Calculator
Add or remove GST and split CGST, SGST, or IGST for Indian transactions.
Open calculatorGST Calculator for Freelancers
Work out GST-inclusive and exclusive values for freelance invoices.
Open calculatorGST Calculator for Restaurants
Estimate GST components for restaurant menu prices and bills.
Open calculatorSIP Calculator
Model SIP growth, step-ups, inflation, invested amount, and potential returns.
Open calculatorCompound Interest Calculator
Calculate compound growth using principal, rate, time, and compounding frequency.
Open calculatorSimple Interest Calculator
Calculate simple interest and the final amount from principal, rate, and time.
Open calculatorIncome Tax Calculator India
Estimate Indian income tax using the assumptions stated on the calculator page.
Open calculatorSalary Hike Calculator
Calculate a raise percentage, increase amount, and revised salary.
Open calculatorCredit Card Interest Calculator
Estimate payoff time and interest cost from balance, APR, and fixed payments.
Open calculatorFuel Cost Calculator
Estimate trip fuel use, total cost, and per-person cost.
Open calculatorDiscount Calculator
Find the sale price, savings, or discount percentage.
Open calculatorTip Calculator
Calculate a tip, total bill, and per-person split.
Open calculatorCurrency Converter
Convert between supported currencies using the rate shown by the tool.
Open calculatorHealth Calculators
Explore common health estimates with clear inputs, context, and limitations.
BMI Calculator
Calculate body mass index using metric or imperial measurements.
Open calculatorBMR & Calorie Calculator
Estimate basal metabolic rate and daily calorie needs.
Open calculatorPregnancy Due Date Calculator
Estimate a due date and pregnancy milestones from the supplied date.
Open calculatorDaily Water Intake Calculator
Estimate daily water intake from the factors requested by the calculator.
Open calculatorDate & Time Calculators
Calculate ages, date differences, working days, countdowns, and milestones.
Date Calculator
Find date differences, add days, calculate working days, and explore milestones.
Open calculatorBusiness Days Calculator
Count or add working days with custom weekends and holiday exclusions.
Open calculatorAge Calculator
Calculate age in years, months, and days from a date of birth.
Open calculatorAge Difference Calculator
Compare two birth dates and calculate the age gap.
Open calculatorDays Until My Birthday
Count the days remaining until the next birthday.
Open calculatorMath & Conversion Calculators
Solve scientific and percentage problems or convert units, numbers, and check amounts.
Scientific Calculator
Use scientific functions, memory controls, and calculation history.
Open calculatorPercentage Calculator
Find a percentage, percentage change, increase, decrease, or ratio.
Open calculatorUnit Converter
Convert common length, weight, temperature, and other units.
Open calculatorNumber to Words Converter
Convert numbers into Indian or international words and cheque-ready rupees.
Open calculatorCheck Writing Amount Converter
Turn a dollar amount into the words used on a check.
Open calculatorHow this directory is maintained
Each card points to a canonical calculator URL. Directory pages and retired widget aliases are not listed as calculators, and the same tool is not repeated across categories.
Calculator results are estimates. Review the formula, assumptions, sources, limitations, and disclaimer on the relevant tool page—especially for financial, tax, and health decisions.
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