Free Physics Calculators
Solve mechanics, wave, and electricity problems instantly. No sign-up, no fees โ just fast, accurate physics tools.
Quick Answer
F = ma (force), v = d/t (velocity), KE = ½mv² (kinetic energy), f = v/λ (frequency).
Enter values into any calculator below for instant results with correct SI units.
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Essential Physics Formulas โ Quick Reference
| Formula | Name | Variables | SI Units | Calculator |
|---|---|---|---|---|
| F = ma | Newton's 2nd Law | Force, mass, acceleration | N, kg, m/s² | Open → |
| v = d/t | Velocity | Velocity, distance, time | m/s, m, s | Open → |
| a = Δv/t | Acceleration | Acceleration, velocity change, time | m/s², m/s, s | Open → |
| KE = ½mv² | Kinetic Energy | Energy, mass, velocity | J, kg, m/s | Open → |
| p = mv | Momentum | Momentum, mass, velocity | kg·m/s | Open → |
| f = v/λ | Wave Frequency | Frequency, wave speed, wavelength | Hz, m/s, m | Open → |
| T = 2π√(L/g) | Pendulum Period | Period, length, gravity | s, m, m/s² | Open → |
| F = kq₁q₂/r² | Coulomb's Law | Force, charges, distance | N, C, m | Open → |
| C = Q/V | Capacitance | Capacitance, charge, voltage | F, C, V | Open → |
All calculators let you solve for any variable. Constants used: g = 9.81 m/s², k = 8.99 × 10&sup9; N·m²/C², c = 3 × 10&sup8; m/s.
Quick Start: Which Calculator Do You Need?
"I need to calculate force"
Use Newton's second law: F = ma. Enter mass and acceleration, or solve for any variable.
Open Force Calculator →"I need velocity or speed"
Calculate velocity from distance and time using v = d/t, or solve for distance or time.
Open Velocity Calculator →"I need to find frequency or wavelength"
Use f = v/λ to convert between frequency, wavelength, and wave speed.
Open Frequency Calculator →"I need to calculate electric force"
Use Coulomb's law: F = kq1q2/r². Enter charges and distance for the electrostatic force.
Open Coulomb's Law Calculator →About PhysCalc
PhysCalc provides free, accurate physics calculators for students, engineers, and educators. From Newton's laws to electromagnetic theory, every tool delivers instant results with no registration required.
Why Use PhysCalc?
- Instant Results: Real-time calculations as you type
- Solve-for Flexibility: Rearrange formulas and solve for any variable
- Accurate Constants: Built-in values for g, k, c, and more
- Three Physics Domains: Mechanics, waves, and electricity
- Free: No registration, no fees, no limits
What Are Physics Calculators?
Physics calculators are online tools that solve standard physics equations by letting you input known variables and computing the unknowns. Instead of rearranging formulas by hand, you select which variable to solve for, enter your values, and get the answer instantly with the correct units. Our calculators cover the three core domains of introductory physics: classical mechanics (force, motion, energy, momentum), wave physics (frequency, wavelength, pendulums, springs), and electricity and magnetism (Coulomb's law, electric fields, capacitance).
For students, these tools serve as a check on homework and exam preparation โ work the problem by hand first, then verify with the calculator. For engineers and professionals, they provide quick reference calculations without needing to look up constants or conversion factors. Every calculator on PhysCalc uses standard SI units and includes built-in physical constants (gravitational acceleration g = 9.81 m/s2, Coulomb's constant k = 8.99 x 10^9 N m2/C2, speed of light c = 3 x 10^8 m/s) so you don't have to remember or look them up.
Frequently Asked Questions
How do I calculate force using F = ma?
Newton's second law states that force equals mass times acceleration: F = ma. If you have a 10 kg object accelerating at 3 m/s2, the net force is 10 x 3 = 30 Newtons. The formula can be rearranged to solve for mass (m = F/a) or acceleration (a = F/m). Our force calculator lets you input any two of the three variables and solves for the third.
What is the difference between speed, velocity, and acceleration?
Speed is how fast an object moves (a scalar, just magnitude). Velocity includes both speed and direction (a vector). Acceleration is the rate of change of velocity over time: a = (v_final - v_initial) / t. An object moving at constant speed in a circle is accelerating because its direction changes, even though its speed is constant. Acceleration is measured in meters per second squared (m/s2).
How do I calculate the frequency of a wave?
Frequency (f) is calculated from wave speed (v) divided by wavelength (lambda): f = v / lambda. For example, a sound wave traveling at 343 m/s with a wavelength of 1 meter has a frequency of 343 Hz. For electromagnetic waves in vacuum, the speed is always c = 3 x 10^8 m/s, so visible light with wavelength 500 nm has frequency 6 x 10^14 Hz.
What is Coulomb's law and how does it work?
Coulomb's law calculates the electrostatic force between two charged objects: F = k x |q1 x q2| / r2, where k is Coulomb's constant (8.99 x 10^9 N m2/C2), q1 and q2 are the charges in Coulombs, and r is the distance between them in meters. Like charges repel (positive force), opposite charges attract (negative force). The force decreases with the square of the distance โ doubling the distance reduces the force to one-quarter.
How do I calculate kinetic energy?
Kinetic energy is the energy of motion, calculated as KE = 0.5 x m x v2, where m is mass in kilograms and v is velocity in meters per second. A 1,000 kg car traveling at 20 m/s (about 45 mph) has KE = 0.5 x 1000 x 400 = 200,000 Joules. Note that kinetic energy increases with the square of velocity โ doubling your speed quadruples your kinetic energy, which is why high-speed collisions are so much more destructive.