All calculators
Every calculator on 1plus1, grouped by topic. Each one shows the formula it uses, the steps it took and the assumptions behind the result.
Mortgage Work out a mortgage payment, the total interest and the full amortisation schedule, with extra payments and taxes included. Loan Work out the payment, total interest and real annual rate of a personal or car loan, fees and extra payments included. Compound interest See what an investment grows to with compound interest, with or without regular contributions, at any compounding frequency. Retirement Estimate how much you need for retirement, what your current savings will grow to, how much to save monthly, or how long your savings will last. Savings Project what your savings will grow to, work out the deposit a goal needs, or find how long that goal will take. Deferred payment loan Work out what a lump sum owed today will cost at maturity, or what a future payoff is worth today, with no periodic payments in between. Auto loan Find the true monthly payment and total cost of a car loan, sales tax, fees, down payment and trade-in included. Payoff time Find out how long it will take to pay off a loan at a fixed monthly payment, and the total interest along the way. Interest rate finder Work out the implicit annual interest rate of a loan from its amount, term and monthly payment alone. APR ↔ APY Convert a nominal annual rate (APR) to its effective annual rate (APY), or the other way around, for any compounding frequency. Future value Find what a lump sum plus regular monthly deposits will grow to at a given interest rate. Present value Find what a future lump sum, a series of future payments, or both together are worth today at a given discount rate. TVM solver Solve for future value, present value, payment, time or rate — pick the unknown and enter the other four. Average return Convert a total investment return over several years into a single annualized (compound) growth rate. Salary converter Convert a salary between hourly, daily, weekly, monthly and annual amounts, adjusted for holidays and vacation. VAT calculator Add tax to a net price to find the gross price, or strip tax out of a gross price to find the net amount. Bond calculator Find a bond's price from its yield, or its yield from its market price, given the coupon rate, face value and maturity. Mutual fund return Project a mutual fund investment's final value after front-load and ongoing expense-ratio fees are taken into account. Auto lease Find the monthly payment for a car lease from the negotiated price, residual value and money factor, split into depreciation and finance charges. Depreciation Depreciate an asset using the straight-line, declining-balance or sum-of-years-digits method, with a year-by-year schedule. Budget calculator Break down your monthly income against spending by category, with a net balance and a debt-to-income ratio. ROI calculator Calculate the return on investment from cost and gain, plus the annualized rate over the holding period. Rent vs. buy Compare the net cost of renting versus buying over time, with the break-even point where buying becomes cheaper.
BMI Work out your body mass index, the WHO category it falls in, and the weight range that matches a healthy BMI for your height. Calories Estimate how many calories you burn in a day and the daily target for losing, holding or gaining weight. Body fat % Estimate body fat percentage from a tape measure using the US Navy method, with the BMI-based method shown for comparison. Ideal weight Compare four classic clinical formulas for ideal body weight — Devine, Robinson, Miller and Hamwi — side by side, as a rough reference. Pregnancy calendar Find your due date and a full week-by-week calendar from your last period, an ultrasound, conception date or IVF transfer. Pregnancy weight gain Find the recommended pregnancy weight gain range by pre-pregnancy BMI, and see how your current gain compares by week. Ovulation calculator Find your fertile window, most likely ovulation day and next period for the current cycle and the six that follow. CANRISK Work out your CANRISK score, the Government of Canada’s validated screening questionnaire for prediabetes and type 2 diabetes risk, from age, weight, waist size, lifestyle, medical and family history. Target heart rate Find your target heart rate zone for exercise from your age and resting heart rate, using the Karvonen method.
Mathematics
Percentages, fractions, equations and numbers Percentage Work out a percentage of a number, a share, a percentage change, or add and subtract a percentage — with every step shown. Fractions Add, subtract, multiply and divide fractions, reduce them to lowest terms, and convert between fractions and decimals. Ratios Simplify a ratio, share a total between any number of parts, or solve a proportion by cross multiplication. Quadratic formula Solve any quadratic equation ax² + bx + c = 0 for its real or complex roots, with the discriminant and every step shown. Log calculator Solve log_b(x) = y for x, y or the base b, with natural log (base e) supported directly. Exponent calculator Solve aⁿ = b for the result, the base or the exponent, with the expanded multiplication shown for whole-number powers. LCM calculator Find the least common multiple of a list of integers, with the prime factorization of each number shown. GCF calculator Find the greatest common factor of a list of integers, and every factor they share, not just the largest. Factor calculator List every divisor of a number, its factor pairs and its prime factorization, all in one place. Scientific notation Convert any number between decimal, scientific notation, E-notation and engineering notation, all shown together. Long division Divide two whole numbers with the quotient, remainder and full long-division steps, digit by digit, shown out. Permutations & combinations Find both the number of permutations (order matters) and combinations (order does not) of r items chosen from n. Confidence interval Find the confidence interval or margin of error for a sample, given its mean, standard deviation and size. P-value calculator Convert a z-score to a p-value, in five common forms at once, or go the other way from a p-value to a z-score. Binary calculator Add, subtract, multiply or divide two binary numbers, or convert a binary number to decimal, with the result shown in both bases. Hex calculator Add, subtract, multiply or divide two hexadecimal numbers, or convert hex to decimal, with the result shown in both bases. Circle calculator Find the radius, diameter, circumference and area of a circle from any one of the four values. Triangle solver Solve any triangle from three known sides, two sides and the angle between them, or two angles and the side between them. Slope calculator Find the slope, angle, distance and equation of a line from two points, or from one point and a known slope. Distance calculator Find the distance between two points in a 2D or 3D plane, or between two latitude/longitude coordinates on Earth. Probability calculator Find the probability of two events combined — union, intersection, complement — or a probability under the normal distribution. Matrix calculator Add, subtract, multiply, transpose, or find the determinant and inverse of a matrix, entered row by row. Scientific calculator Type a full expression — trigonometry, logarithms, powers and roots — and get an exact result, with proper order of operations. Function study A full study of a polynomial function — domain, zeros, derivative, critical points, second derivative and convexity — the way a class works through it. Simplex solver Solve a linear programming problem — maximize or minimize a linear objective under "less than or equal to" constraints. Statistics Paste a series of numbers and read its mean, median, spread, quartiles, skewness and outliers at a glance. Discount Find the sale price, the percentage off, or the price before the discount — including stacked offers and sales tax.
Date and time
Age, durations, deadlines and hours workedUnit conversion
Length, weight, volume, temperature, energy and more Unit converter Convert between metric, imperial and US units across fourteen categories — length, weight, volume, speed, energy and more. Temperature Convert between Celsius, Fahrenheit, Kelvin and Rankine, with the formula, the substitution and a table of familiar reference points. Fuel cost Work out what a trip will cost in fuel, or find your car’s real consumption from a fill-up, in litres or gallons.
Area Find the area and perimeter of nine common shapes, entering each dimension in whatever unit you have to hand. Volume Find the volume and capacity of eight solids, from a packing box to a cylindrical tank, in any unit you need. Right triangle Solve a right triangle from any two measurements: the missing side, both angles, the area and the perimeter.
Construction
Concrete, paint, materials and surfaces Area Find the area and perimeter of nine common shapes, entering each dimension in whatever unit you have to hand. Volume Find the volume and capacity of eight solids, from a packing box to a cylindrical tank, in any unit you need. Right triangle Solve a right triangle from any two measurements: the missing side, both angles, the area and the perimeter. Concrete dimensioning Concrete volume and cement bags, sand and gravel from a slab size and mix ratio. Beam bending Reactions, shear and maximum bending moment for a simply supported beam. Earthwork volume Excavation or backfill volume from an area and depth, with a swell or compaction factor.
Everyday life
Tips, discounts, fuel and splitting the bill Tip Work out a tip, split the bill between any number of people, and round the total or the share to a clean amount. Discount Find the sale price, the percentage off, or the price before the discount — including stacked offers and sales tax. Fuel cost Work out what a trip will cost in fuel, or find your car’s real consumption from a fill-up, in litres or gallons.
Chemistry
Molar mass, dilutions and pHTelecom & networks
IP subnetting, RF link budget and fiber lossPharmacy
Dosing, infusion rates and dilutions86 calculators