Calculators
Loan, EMI, interest, GST, discount, BMI and percentage calculators with clear, step-by-step results.
24 tools · all free, all run in your browser
Aspect Ratio & Crop Calculator
Work out an image or video's aspect ratio, or the crop dimensions needed to hit a target ratio.
Open toolAverage Calculator
Find the mean, median, mode, range and standard deviation of any list of numbers.
Open toolBMI Calculator
Calculate Body Mass Index in metric or imperial units and see the healthy weight range for your height.
Open toolBMR & Calorie Calculator
Estimate your basal metabolic rate and daily calorie needs using the Mifflin-St Jeor equation.
Open toolCompound Interest Calculator
Project how savings or investments grow over time with compounding and regular contributions.
Open toolDimensional Weight Calculator
Work out a parcel's billable shipping weight from its size, the way carriers actually charge.
Open toolDiscount Calculator
Find the sale price and how much you save, including stacked discounts and final price with tax.
Open toolElectricity Cost Calculator
Work out how much an appliance costs to run, per day, month and year, from its wattage and your rate.
Open toolEMI Calculator
Calculate your monthly loan instalment, total interest and full repayment schedule for any loan.
Open toolFuel Cost Calculator
Estimate the fuel cost of a trip from distance, fuel efficiency and price per unit.
Open toolGPA Calculator
Calculate your grade point average from letter grades and credit hours on the standard 4.0 scale.
Open toolGST / VAT Calculator
Add or remove GST, VAT or sales tax from any amount and see the tax component clearly.
Open toolHourly to Salary Converter
Convert pay between hourly, daily, weekly, monthly and annual amounts.
Open toolLoan Calculator
See what a loan really costs — monthly payment, total interest and the payoff schedule over time.
Open toolMortgage Affordability Calculator
Estimate how much home you can afford based on your income, debts and down payment.
Open toolOne-Rep Max Calculator
Estimate your one-rep max from any weight and rep count using the Epley and Brzycki formulas.
Open toolPaint Calculator
Work out how much paint you need for a room from its dimensions, doors and windows.
Open toolPercentage Calculator
Work out percentages, percentage change and 'X is what percent of Y' with the working shown.
Open toolPrint Size & DPI Calculator
Work out what size a photo will print at a given resolution, or what resolution you need for a target size.
Open toolProfit Margin Calculator
Work out gross profit, margin and markup from cost and selling price — or find the price you need.
Open toolRunning Pace Calculator
Work out your running pace and speed, then predict your finish time for other race distances.
Open toolSimple Interest Calculator
Calculate simple interest and the total amount payable using the classic P × R × T formula.
Open toolTimesheet Calculator
Turn clock-in and clock-out times into total hours worked per day and for the week, with optional pay.
Open toolTip Calculator
Work out the tip and split the bill evenly between any number of people.
Open toolThese calculators cover the arithmetic that decides real money and real decisions: what a loan actually costs once interest is included, how much a stacked discount really saves, what margin a price leaves you, and how an investment compounds over twenty years. Rather than returning a bare number, each one shows the working, the breakdown and — where it applies — a year-by-year schedule, so you can see where the figure comes from and sanity-check it against a quote you have been given.
Borrowing and repayment
The cost of a loan is dominated by two things people underestimate: the term and the direction of early payments. Because interest is charged on the outstanding balance, the first years of a long loan are mostly interest and barely touch the principal. Extending a term lowers the monthly payment but can dramatically increase the total repaid. The amortisation schedules here make both effects visible, and let you test what an extra payment each month would actually save.
Percentages, margins and pricing
Percentages are where quick mental maths most often goes wrong. Stacked discounts do not add — 20% then 10% is 28% off, not 30%. Margin and markup are not the same measure: a 50% markup on cost is only a 33.3% margin on the selling price. A rise and an equal-sized fall do not return you to the starting figure, because each applies to a different base. Each calculator here states which convention it is using so the result is unambiguous.
Estimates, not advice
Every financial figure produced here is an estimate based purely on the numbers you enter. Real lenders add processing fees, insurance and taxes, and quote an APR that folds those in; real investments carry fees, tax and sequence risk that a smooth projection cannot capture. Health measures such as BMI are population-level screening indicators rather than diagnoses. Use these tools to understand the shape of a decision, then confirm the specifics with a qualified professional.