Calculators

23 free in-browser calculators — compute percentages, split bills, check BMI, project compound interest, and estimate loan repayments. Instant results, no account needed.

5 modes

Percentage Calculator

Calculate X% of Y, find what percentage X is of Y, compute percentage change, and increase or decrease values by a percentage.

Use tool
Bill splitter

Tip Calculator

Enter a bill amount, choose a tip percentage, and split by any number of people. Shows tip amount, total bill, and per-person cost.

Use tool
Metric & imperial

BMI Calculator

Calculate your Body Mass Index from height and weight. Supports metric and imperial units. Shows BMI category and healthy weight range.

Use tool
Year-by-year

Compound Interest Calculator

Calculate how investments grow with compound interest. Choose compounding frequency, enter rate and time, and see year-by-year growth.

Use tool
Amortization

Loan Calculator

Calculate monthly loan payments, total interest paid, and view an amortization breakdown for any loan amount, rate, and term.

Use tool
Exact age

Age Calculator

Calculate your exact age in years, months, and days from your date of birth. Shows days until your next birthday and the day of the week you were born.

Use tool
Days & weeks

Date Difference Calculator

Calculate the exact difference between two dates in days, weeks, months, and years. Useful for deadlines, durations, and event planning.

Use tool
Sale price

Discount Calculator

Calculate the sale price after a percentage discount, or find what percentage discount was applied. Shows original price, discount amount, and final price.

Use tool
Add & remove

Sales Tax Calculator

Add or remove sales tax from a price. Enter the pre-tax or post-tax amount and the tax rate to calculate the other value instantly.

Use tool
BMR & TDEE

Calorie Calculator (BMR & TDEE)

Calculate your Basal Metabolic Rate (BMR) and Total Daily Energy Expenditure (TDEE) using the Mifflin-St Jeor equation. Shows calorie targets for weight goals.

Use tool
Trip cost

Fuel Cost Calculator

Calculate the fuel cost of a road trip based on distance, vehicle fuel efficiency, and price per litre or gallon. Supports metric and imperial units.

Use tool
Overtime ready

Hours Calculator

Calculate total hours worked between a start and end time. Subtract break time and see your hours in decimal and HH:MM format. Supports overnight shifts.

Use tool
Best deal finder

Unit Price Calculator

Compare the price per unit across multiple items to find the best deal. Enter price and quantity for up to three products — instantly highlights the cheapest option.

Use tool
Any appliance

Electricity Cost Calculator

Calculate how much it costs to run any appliance. Enter wattage, daily usage hours, and your electricity rate to get hourly, daily, monthly, and annual costs.

Use tool
Bidirectional

Salary Calculator

Convert between annual salary, monthly pay, weekly pay, and hourly wage. Accounts for working hours per week and weeks per year for accurate conversions.

Use tool
3-way solver

Margin Calculator

Calculate profit margin, gross profit, and markup from cost and revenue. Enter any two values to compute the third. Essential for pricing and business planning.

Use tool
Annualised rate

ROI Calculator

Calculate the return on investment for any investment. Enter initial cost, final value, and time period to get total ROI and annualised return rate.

Use tool
Month-by-month

Savings Goal Calculator

Find out how long it will take to reach a savings goal. Enter your target amount, current savings, monthly contribution, and interest rate.

Use tool
Weighted GPA

GPA Calculator

Calculate your weighted GPA by entering courses with letter grades and credit hours. Supports 4.0 scale. Add or remove courses dynamically.

Use tool
Final exam needed

Grade Calculator

Calculate your current weighted grade, what score you need on the final exam to reach a target grade, and your overall course percentage.

Use tool
3-way solver

Speed, Distance & Time Calculator

Solve for speed, distance, or time given any two values. Supports km/h, mph, m/s, and knots. Instantly calculates the missing value.

Use tool
Room coverage

Paint Calculator

Calculate how many litres or gallons of paint you need for a room. Enter wall dimensions, number of coats, and coverage rate per litre.

Use tool
Slabs & columns

Concrete Calculator

Calculate the volume of concrete needed for slabs, footings, and columns. Shows cubic metres and cubic feet, and the number of standard bags required.

Use tool

About these calculators

Every calculator runs entirely in your browser. Results update as you type — no form submissions, no server round-trips. The financial calculators (compound interest, loan) use standard actuarial formulas used by banks and financial institutions worldwide.

Are the financial results accurate enough for real decisions?

The formulas are mathematically correct, but real loans and savings accounts involve fees, variable rates, tax implications, and rounding rules that vary by lender and jurisdiction. Use these tools for planning and estimation; always verify with your bank or a qualified financial adviser before committing.

What BMI categories does the BMI calculator use?

The calculator uses the WHO classification: Underweight (<18.5), Normal weight (18.5–24.9), Overweight (25–29.9), Obese (≥30). BMI is a population-level screening tool and does not account for muscle mass, bone density, age, or ethnicity. Consult a healthcare professional for personalised health assessments.

What compounding frequency does the compound interest calculator use?

You can choose annual, quarterly, monthly, or daily compounding. Most savings accounts compound monthly or daily. More frequent compounding produces slightly higher returns for the same nominal interest rate — the difference is most significant over long time horizons.

Browse other categories