How to use Physics Calculator
Choose a relationship, set the unknown in Solve for, enter the remaining values with their units, then click Calculate. The result shows the selected formula, values converted to base units, the calculation expression, and the answer. Reset returns the page to Force mode.
- Choose a relationship from Formula / calculation.
- Choose the unknown quantity in Solve for. That quantity is removed from the input fields.
- Enter each remaining value and choose its compatible unit when a unit selector appears.
- Click Calculate and review the result, formula, and steps.
- Use Copy result or Download result (.txt) to keep the plain-text output. Use Reset to return to Force mode.
What can Physics Calculator calculate?
The 16 modes cover force, acceleration, momentum, kinetic energy, potential energy, work, power, pressure, density, the ideal gas law, Ohm's law, voltage drop, battery runtime, wave speed and wavelength, photon energy, and half-life. Each mode lists its formula variables in Solve for, so the unknown can be a different quantity each time.
For example, select Force (F = m x a), keep Force (F) in Solve for, enter Mass (m) as 10 with Kilograms (kg), and enter Acceleration (a) as 9.8 with m/s2.
F = m x a
F = 10 x 9.8
Force = 98 Newtons (N)How Solve for and units change the calculation
Solve for lists the variables in the selected mode and removes the chosen target from the input fields. The other values are converted to base units before calculation. Physics Calculator shows the result in the target variable's default unit; it has no result-unit selector. Remaining quantity (N) and Initial quantity (N0) in Half-Life have no unit selector because the code treats them as unitless.
Potential energy uses g = 9.80665 m/s2. Ideal gas calculations use R = 0.0820573660809596 L atm mol-1 K-1 and convert temperature to Kelvin. Photon energy uses h = 6.62607015 x 10-34 J s. Battery Runtime uses capacity divided by current and assumes a constant discharge current, as stated in its mode note.
What input does Physics Calculator accept?
Enter signed decimal text such as 10, 0.25, or -3. Empty fields, comma-formatted values, and scientific notation such as 1e3 fail validation. The selected mode then applies its own rules: positive fields such as mass, area, volume, and resistance must be greater than zero; nonnegative fields cannot be below zero; gas temperatures must be above absolute zero; and work angles must be between 0 and 180 degrees.
Half-Life rejects a Remaining quantity (N) greater than Initial quantity (N0). Some rearrangements need a nonzero known value. An impossible work-angle result, a non-finite result, or a result that violates a mode's positive-value rule produces an error instead of a result.
When to use Physics Calculator
Choose this page for one formula at a time, such as calculating force from mass and acceleration, then checking kinetic energy from the same object's mass and velocity.
The electrical modes cover a single voltage, current, resistance, wire-resistance, or runtime relationship. For several circuit components, the Electrical Calculator covers resistor combinations, voltage drop, wire-size estimates, battery runtime, and energy consumption.
For one gas-law calculation, the Ideal Gas Law Calculator focuses on that relationship. For decay quantities, the Half-Life Calculator uses initial amount, half-life, and elapsed time. Browse Science Calculators when the relationship belongs to chemistry, optics, fluids, or another science category.
Frequently asked questions
How do I calculate force from mass and acceleration?
Choose Force (F = m x a) in Formula / calculation, select Force (F) in Solve for, enter Mass (m) and Acceleration (a), then click Calculate. The result uses F = m x a after unit conversion.
Can Physics Calculator solve for any variable?
Yes. Solve for lists the variables in the selected formula, and the chosen variable is removed from the input fields. Enter the remaining known values and the calculator rearranges that relationship around the target.
Why does Physics Calculator reject 1e3 or 1,000?
The input parser accepts signed decimal text. Scientific notation and comma-formatted numbers fail validation, so enter 1000 instead.
Does Physics Calculator send my calculation values anywhere?
The page does not send calculation inputs with fetch, XMLHttpRequest, sendBeacon, or a form submission. The generated result says that the calculation is performed locally in your browser using a fixed physics formula.