New Calculators

Calculate the volume, slant height, and lateral surface area of a cone from its radius and height — volume = (1/3)πr²h, slant height = √(r²+h²), lateral surface = πrl.

Calculate the volume, surface area, face diagonal, and space diagonal of a cube from its side length — volume = s³, surface area = 6s², face diagonal = s√2, space diagonal = s√3.

Calculate the surface area, volume, and space diagonal of a cuboid (rectangular box) from its length, width, and height — surface area = 2(lw+lh+wh), volume = lwh, diagonal = √(l²+w²+h²).

Calculate the total surface area, lateral surface area, and base area of a cylinder from its radius and height — total = 2πr² + 2πrh, lateral = 2πrh, base = πr².

Calculate the volume, lateral surface area, and total surface area of a cylinder from its radius and height.

Convert data transfer rates between bit/s, kbit/s, Mbit/s, Gbit/s, B/s, kB/s, MB/s, and more — instantly, and see why a 100 Mbit/s line downloads at only 12.5 MB/s.

Calculate density from mass and volume — density = mass ÷ volume, in kilograms per cubic metre (kg/m³).

Calculate the straight-line (Euclidean) distance between two points (x1, y1) and (x2, y2) — distance = √((x2−x1)² + (y2−y1)²) — plus the horizontal and vertical legs.

Convert your dog's age into human years with a size-aware calculator based on the AKC method.

Estimate how long a file takes to download at your connection speed, with the bits-vs-bytes conversion handled for you and the time shown in minutes and seconds.

Calculate efficiency from useful output and total input — efficiency = (output ÷ input) × 100, as a percentage (%).

Work out what an appliance costs to run per day, month, and year from its wattage, daily run time, and your price per kilowatt-hour.

Calculate the area and circumference of an ellipse from its two semi-axes — area = πab, with Ramanujan's accurate perimeter approximation.

Convert energy between joule, kilojoule, megajoule, calorie, kilocalorie, watt-hour, kilowatt-hour, BTU, and foot-pound — instantly and with exact, joule-based conversion factors.

Calculate the area, height, and perimeter of an equilateral triangle from its side length — area = (√3/4)s², height = (√3/2)s, perimeter = 3s.

Calculate base raised to an exponent (base ^ exponent) — including negative and fractional exponents — with a worked example.

Calculate n! (n factorial) — the product of all positive integers up to n, with 0! = 1 by definition. Supports values from 0! up to 170!.

Find the nth Fibonacci number F(n) with F(0) = 0 and F(1) = 1 — the sequence 0, 1, 1, 2, 3, 5, 8, 13 where each term is the sum of the two before it.

Convert force between newton, kilonewton, dyne, kilogram-force, pound-force, and more — instantly and with exact, newton-based conversion factors.

Calculate the distance an object falls and the velocity it reaches in free fall after a given time, ignoring air resistance — distance = ½ × g × t² and velocity = g × t.

Convert frequency between hertz, kilohertz, megahertz, gigahertz, terahertz, and rpm — instantly and with exact, hertz-based conversion factors.

Find the greatest common factor (GCF) and least common multiple (LCM) of two integers using the Euclidean algorithm, with the full working shown.

Find the nth term and the sum of the first n terms of any geometric sequence from its first term and common ratio.

Work out how much grass seed you need to sow or overseed a lawn — the amount in kilograms and grams, based on your lawn area and seed rate.

Work out how much gravel you need to cover an area to a given depth — the volume in cubic metres and the weight in tonnes, based on the stone's density.

Calculate heat energy in joules from mass, specific heat, and temperature change using Q = m × c × ΔT.

Calculate the volume, curved surface, and total surface area of a hemisphere from its radius using V = 2/3 × π × r³, A = 2 × π × r², and total = 3 × π × r².

Calculate spring force and elastic potential energy from a spring constant and displacement using Hooke's law — force = k × x and PE = ½ × k × x².

Calculate impulse — J = F × Δt — the force applied over a time interval, which equals the change in momentum (N·s = kg·m/s).

Calculate the energy stored in an inductor's magnetic field (E = ½LI²) in joules from its inductance and the current flowing through it.

Calculate the kinetic energy (KE = ½mv²) in joules and the linear momentum of a moving object from its mass and velocity.

Solve the thin-lens equation (1/f = 1/dₒ + 1/dᵢ) for the image distance and magnification from a focal length and object distance.

Calculate profit margin and markup from a cost and a selling price, with the profit per unit shown alongside.

Calculate the margin of error for a proportion from the sample proportion p, the sample size n, and a z-score — MoE = z × √(p(1 − p) ÷ n) × 100.

Calculate the selling price and profit from a cost and a markup percentage, with a clear explanation of how markup differs from margin.

Calculate the rest energy of a mass with Einstein's mass-energy equivalence — energy = mass × c², where c is the speed of light.

Calculate mechanical advantage from load and effort force — MA = load force ÷ effort force.

Find the midpoint of the line segment between two points (x1, y1) and (x2, y2) — midpoint = ((x1 + x2) / 2, (y1 + y2) / 2) — the exact centre halfway between them.

Calculate molarity from moles and volume — molarity = moles ÷ litres of solution, in moles per litre (mol/L, also written M).

Work out how much mulch you need to cover a bed — in cubic yards, cubic feet, and standard 2-cubic-foot bags — from the area and the depth you want.

Calculate the net force on an object from its mass and acceleration using Newton's second law — force = mass × acceleration (F = m × a).

The complete Ohm's law solver. Pick which two of voltage (V), current (I), resistance (R), and power (P) you know, enter them, and get the other two instantly — V = I × R, P = V × I, and every rearrangement.

Calculate the total capacitance of two capacitors in parallel — they simply add: C = C1 + C2.

Calculate the area of any parallelogram from its base and perpendicular height using the formula area = base × height.

Calculate the period and frequency of a simple pendulum from its length — period = 2π√(L ÷ g) and frequency = 1 ÷ period.

Calculate percent error between an experimental (measured) value and a theoretical (true) value — percent error = |measured − true| ÷ |true| × 100%.

Calculate the percentage difference between two values — a symmetric comparison relative to their average.

Calculate the number of permutations P(n, r) — how many ways to arrange r items chosen from n when order matters, using P(n, r) = n! ÷ (n − r)!.

Work out the exact flour, water, salt, and yeast weights for any number of pizza dough balls using baker's percentages.

Calculate the gravitational potential energy of an object from its mass and height — PE = m × g × h, with g = 9.80665 m/s², in joules.