Weight Tool
Find the gravitational force acting on a given mass, or derive mass from a known force. Explore gravity presets and custom acceleration, compare celestial bodies, review graphical results and tables, and export the calculated data.
| Environment | Gravity (m/s²) | Weight (N) | Weight (lbf) | Earth % |
|---|
Table of Contents
Highlights
- Calculate weight from mass or determine mass from a known force.
- Compare gravity across ten celestial environments and custom settings.
- Visualise selected and comparison weights with responsive charts.
- Explore detailed gravitational-force tables and Earth-relative percentages.
- Export results as CSV, JSON, TXT or SVG charts.
How Weight Tool Works?
Weight is the force of gravity acting on mass. The calculation uses Newton's relationship between mass and gravitational acceleration:
Here W is weight in newtons (N), m is mass in kilograms (kg), and g is gravitational acceleration in metres per second squared (m/s²). When a force is provided instead of mass, the tool determines mass from , provided gravity is greater than zero.
For example, a 70 kg mass under standard Earth gravity of 9.80665 m/s² weighs 686.4655 N. Its mass stays 70 kg on the Moon, where the preset acceleration is 1.62 m/s², but its weight becomes 113.4 N. Relative Earth gravity is calculated as:
The selected environment determines the main weight result. The comparison environment supplies a second force result. The chart and table apply each preset gravitational acceleration to the same mass, so differences reflect gravity rather than changes in mass.
| Environment | Preset gravity (m/s²) | Weight of 70 kg (N) |
|---|---|---|
| Earth | 9.80665 | 686.4655 |
| Moon | 1.62 | 113.4 |
| Mars | 3.721 | 260.47 |
| Jupiter | 24.79 | 1735.3 |
Available presets include Earth, Moon, Mars, Mercury, Venus, Jupiter, Saturn, Uranus, Neptune and Sun. You can also enter a custom non-negative gravitational acceleration. Display precision can be set to 2, 3, 4 or 6 decimal places.
Practical Use Cases
Physics students: Compare the weight of an object on Earth, the Moon and Mars to understand why mass remains unchanged while gravitational force varies.
Science teachers: Demonstrate the relationship between weight and gravitational acceleration using the side-by-side visual, environment chart and numerical table.
Space enthusiasts: Estimate how strongly a specified mass would be pulled at the preset gravity of different planets or the Sun.
Engineers: Assess gravitational loading at a custom acceleration and inspect the result alongside standard Earth gravity, including when starting from a known force.
Researchers and technical writers: Generate reproducible comparison data, review chosen decimal precision and export results as CSV, JSON, TXT or an SVG chart for reports.
Accuracy and Limitations
The tool uses W = mg with fixed preset gravitational accelerations and standard Earth gravity of 9.80665 m/s². Results are exact for the supplied mass and gravity within floating-point precision, but displayed values are rounded to the selected 2, 3, 4 or 6 decimal places. Planetary presets are representative values, not location-specific measurements: gravity can vary with altitude, latitude and local conditions. The simple model does not account for buoyancy, rotation-related effects, changing gravity with height, or atmospheric drag. Negative inputs are rejected; deriving mass from force requires non-zero gravity. At zero gravity, a mass has zero calculated weight.
