Free Online Calculators

Auto Loan CalculatorEstimate a vehicle loan with price, down payment, trade-in value, sales tax, fees, APR and term, with monthly payment, financed amount, interest and amortization breakdown. Retirement CalculatorProject retirement savings from a starting balance, recurring contributions, annual return, inflation and time horizon, with nominal and inflation-adjusted results. Amortization CalculatorBuild a fixed-rate loan amortization schedule with monthly payment, principal and interest split, remaining balance and optional extra principal payments. Interest Rate CalculatorEstimate the annual nominal interest rate implied by a principal, fixed periodic payment and loan term using a numeric solve for standard amortizing loans. Salary CalculatorConvert gross pay between hourly, daily, weekly, biweekly, monthly and annual rates using configurable hours per day, days per week and working weeks per year. Ideal Weight CalculatorCompare several established adult ideal-weight formulas and a BMI-based reference range from height and sex reference inputs, with clear non-medical limitations. BMR CalculatorEstimate basal metabolic rate with the Mifflin–St Jeor equation from age, height, weight and sex reference inputs, with metric or imperial measurements. Prime Number CheckerCheck whether a positive integer is prime, calculate its prime factorization and list nearby prime numbers for ordinary math and learning tasks. GCD & LCM CalculatorCalculate GCD and LCM for two or more integers using the Euclidean algorithm, with normalized values and a compact result explanation. Quadratic Equation SolverSolve quadratic equations from a, b and c coefficients with discriminant, real or complex roots, vertex, axis of symmetry and a plotted parabola preview. Matrix CalculatorWork with editable 2×2 and 3×3 matrices to add, subtract, multiply, transpose, calculate determinants and find inverses when they exist. Probability CalculatorCalculate common independent-event probabilities including complements, both, either and at least one, with percentage inputs and formula breakdowns. Electricity Cost CalculatorEstimate appliance energy consumption and cost from power, quantity, daily usage, number of days and electricity rate, with daily, monthly and annual projections. Time Card CalculatorCalculate daily and weekly work hours from one or two shifts per day, deduct breaks, apply weekly or daily overtime rules, estimate gross pay and export a CSV time card. Graphing CalculatorPlot up to six mathematical functions with separate colors, pan and zoom the coordinate plane, control the viewing window, evaluate functions at x values and export the graph as PNG. Random Number GeneratorGenerate up to 10,000 random integers or decimal values between custom limits, optionally require unique values, sort results and copy or download the list. Standard Deviation CalculatorCalculate sample or population standard deviation plus variance, mean, median, count, minimum, maximum and sum from pasted numeric data. Budget PlannerPlan a monthly budget with editable income and expense categories, live totals, savings or shortfall, category percentages and downloadable CSV. Triangle CalculatorSolve common SSS, SAS and ASA/AAS triangle cases, calculate missing sides and angles, area and perimeter, and review a proportional result diagram. Concrete CalculatorEstimate concrete required for slabs, pads and rectangular pours using metric or imperial dimensions, quantity and waste allowance, with cubic metre, foot and yard totals. Body Fat CalculatorEstimate body fat percentage with the US Navy circumference method, metric or imperial measurements, reference ranges and a clear measurement guide. Calorie CalculatorEstimate basal metabolic rate, maintenance calories and simple gain or loss targets from age, sex, height, weight and activity level. Running Pace CalculatorCalculate pace per kilometre and mile, average speed and equivalent finish times from a completed or planned running distance and duration. Fuel Cost CalculatorEstimate fuel required and driving cost for a trip using metric L/100 km, US MPG or UK MPG, local fuel price and optional round-trip distance. Unit Price CalculatorCompare several products by normalized unit price across compatible weight, volume or count units and clearly highlight the lowest-cost option. Water Intake CalculatorEstimate a general daily hydration target from body weight, exercise time and climate, with litres, millilitres and fluid ounces plus a clear caution. Dice RollerRoll multiple standard tabletop dice or a custom number of sides, view each die, total the roll and keep a short browser-side history. Coin FlipFlip one or many virtual coins with browser randomness and review heads, tails, percentages and a compact result sequence. Roman Numeral ConverterConvert whole numbers to Roman numerals and Roman numeral strings back to numeric values with instant validation. GPA CalculatorCalculate GPA from letter grades and course credits on a 4.0 or 5.0 scale with weighted credit-hour math. Grade CalculatorConvert earned and possible points into a percentage and letter grade, with optional weighted-grade contribution. Salary to Hourly CalculatorConvert annual salary to an equivalent hourly rate or hourly pay to annual salary using configurable work hours and weeks. Percentage CalculatorCalculate a percentage of a number, find what percentage one value is of another, measure percentage change, or increase/decrease a value by a percentage. BMI CalculatorCalculate BMI using metric or imperial weight and height inputs and view the standard screening category. Loan CalculatorEstimate scheduled loan payments, optional extra monthly payments, payoff timing, total interest and a detailed amortization schedule. Discount CalculatorCalculate successive percentage discounts, fixed coupons, tax and savings, or reverse a known final price back to the estimated original price. Profit Margin CalculatorCalculate profit, margin, markup, fees and break-even pricing, or solve selling price and maximum cost for a target margin. Mortgage CalculatorEstimate mortgage principal and interest plus optional property tax, insurance and HOA costs with loan amount, down payment and lifetime interest. EMI CalculatorCalculate a fixed monthly EMI from principal, annual interest rate and installment term with total interest and repayment. Compound Interest CalculatorProject compound growth with selectable compounding frequency and optional recurring monthly contributions. Simple Interest CalculatorCalculate simple interest and final amount from principal, annual rate and time using the standard P × r × t relationship. Savings CalculatorProject savings from a starting balance, monthly deposits, time horizon and assumed annual return with contributions versus growth. Investment CalculatorEstimate the recurring monthly contribution needed to reach an investment target from a starting amount, return assumption and time horizon. ROI CalculatorCalculate net profit, ROI and optional annualized return using investment cost, proceeds, income, fees and holding period. APR CalculatorEstimate effective APR by solving the monthly yield implied by scheduled payments and upfront lender fees. Loan Comparison CalculatorCompare two fixed-rate loans side by side by monthly payment, interest, fees, term and estimated lifetime cost. Mortgage Payoff CalculatorEstimate payoff time and interest savings when making an extra monthly payment on an existing fixed-rate mortgage or loan. Debt Payoff CalculatorBuild a debt avalanche or snowball payoff plan from multiple balances, APRs, minimum payments and an extra monthly budget. VAT CalculatorAdd VAT to a net price or reverse VAT from a tax-inclusive total with a custom percentage rate. Sales Tax CalculatorAdd sales tax to a base amount or extract included tax from a known tax-inclusive total. Tip CalculatorCalculate a tip, bill total and optional per-person split from a custom tip percentage. Commission CalculatorCalculate commission from sales or reverse a target commission into the sales amount required. Markup CalculatorCalculate selling price from cost and markup or derive markup and profit margin from a known selling price. Break-even CalculatorCalculate break-even units and revenue from fixed costs, unit price and variable cost with an optional target-profit scenario. Average CalculatorCalculate count, sum, arithmetic mean, median, minimum, maximum and range from a pasted list of numbers. Ratio CalculatorSimplify integer ratios, calculate A divided by B and scale a ratio to a new first value. Proportion CalculatorSolve any missing value in A/B = C/D using cross multiplication with a clear result. Fraction CalculatorAdd, subtract, multiply or divide two fractions and return a simplified fraction, decimal and mixed number where useful. Scientific CalculatorEvaluate scientific expressions safely without eval, including powers, parentheses, trigonometry, logarithms, square roots and constants.