Free Online Calculators

Loan Calculator

Estimate your monthly loan payment and total interest from the amount, rate, and term you enter. Standard amortization formula, documented rounding.

Monthly Payment Calculator

Find the monthly payment for a loan — or flip it: from the payment you can afford, find the loan amount it supports. Same amortization math, both directions.

Compound Interest Calculator

Project growth with compound interest: choose the compounding frequency, add optional periodic contributions, and see principal vs interest clearly.

Salary Calculator

Convert pay between hourly, daily, weekly, monthly, and annual figures with your own hours and weeks — plus an optional deduction rate you control.

VAT Calculator

Add VAT to a net price or extract VAT from a gross price using the rate that applies in your country. Instant, free, and private.

Discount Calculator

Calculate the final price after a discount — including stacked double discounts, the amount you save, and the true effective discount rate.

Tip Calculator

Free tip calculator: pick a tip percent, see the tip amount, the total with tip, and each person's share when splitting the bill — instantly in your browser.

Savings Goal Calculator

Free savings-goal calculator: how much to put aside each month to reach a target amount by a deadline, with or without an expected return — in your browser.

Inflation Calculator

Free inflation calculator: enter an amount, your own assumed annual rate, and years — see future purchasing power, the equivalent future amount, and total price change.

Debt Payoff Calculator

Free debt payoff calculator: from balance, APR, and monthly payment, see how many months until debt-free, the total you will pay, and the interest cost — instantly.

Net Worth Calculator

Free net worth calculator: enter total assets and total liabilities to see your net worth and debt-to-asset ratio. Your numbers stay in your browser.

Savings Rate Calculator

Free savings rate calculator: enter your period income and the amount you saved to see your savings rate as a percentage and how much you spent.

CAGR Calculator

Free CAGR calculator: enter a beginning value, ending value, and number of years to get the compound annual growth rate and the total growth over the period.

Emergency Fund Calculator

Free emergency fund calculator: enter your monthly expenses, the months of cover you want, and current savings to see your target fund, shortfall, and months already covered.

BMI Calculator

Calculate body mass index in metric or imperial units and see where it falls in the WHO adult ranges — with the limits of BMI stated honestly.

Calorie Calculator

Estimate your resting metabolism (BMR), daily maintenance calories (TDEE), and a gradual goal target using the Mifflin-St Jeor equation.

BMR Calculator

Free BMR calculator using the Mifflin-St Jeor equation: the calories your body burns at complete rest, from weight, height, age, and sex — in your browser.

Body Fat Calculator

Free body-fat calculator using the US Navy circumference method: estimate body-fat percent from height, waist, neck (and hip) — computed in your browser.

Ideal Weight Calculator

Free ideal weight calculator showing Devine, Robinson, Miller, and Hamwi estimates side by side from your height and sex — with the formulas' clinical origin explained honestly.

Target Heart Rate Calculator

Free target heart rate calculator: research-backed maximum heart rate (208 − 0.7×age, Tanaka) and your personal training zone via the Karvonen heart-rate-reserve method.

Profit Margin Calculator

Compute profit, margin (share of revenue), and markup (share of cost) from cost and selling price — and stop confusing the two.

Break-even Calculator

Find how many units you must sell to cover fixed costs, from price and variable cost per unit — with impossible price setups flagged honestly.

ROI Calculator

Compute return on investment from cost and final value, with an optional holding period for the annualized rate that makes investments comparable.

ROAS Calculator

Compute return on ad spend and — from your profit margin — the break-even ROAS below which ads lose money even when revenue looks healthy.

Google Ads Budget Calculator

Work backwards from target conversions: your conversion rate and your average CPC give the clicks and budget required, monthly and daily.

CAC Calculator

Compute customer acquisition cost from total marketing and sales spend, and optionally the LTV:CAC ratio investors actually look at.

CPM Calculator

Solve any of cost, impressions, or CPM from the other two. The standard cost-per-mille formula, instantly and privately in your browser.

CPC Calculator

Solve cost, clicks, or cost-per-click from the other two values — the basic unit economics of any paid traffic campaign.

Percentage Calculator

Free percentage calculator: find X% of a number, what percent one number is of another, and percentage change — instantly in your browser.

Unit Converter

Convert length, weight, volume, area, speed, temperature, and data units using exact international definitions — factors documented on the page.

Fuel Economy Calculator

Free fuel-economy calculator: convert L/100km to US MPG and back, and estimate the fuel and cost of any trip from distance, consumption, and price per liter.

GPA Calculator

Free GPA calculator: enter up to six courses with grade points and credits and get your weighted GPA on your own scale — 4.0, 5.0, or 20-point — instantly in your browser.

Percentage Change Calculator

Free percentage change calculator: enter an old value and a new value to get the percent increase or decrease and the absolute change, rounded for display.

Age Calculator

Calculate exact age in years, months, and days with true calendar arithmetic — plus total days lived and a countdown to the next birthday.

Date Calculator

Count days between two dates, add or subtract days, months, or years, and count Mon–Fri workdays — with every calendar convention stated.