Weight Calculator

Calculate weight from mass and gravitational acceleration. Understand the difference between mass and weight across different celestial bodies.

Weight Calculation

Calculation Method

Mass

Gravitational Acceleration

Quick Examples

Results

686.7

Mass

70 kg

Gravity

9.81 m/s²

Weight in Different Units

686.7 N

154.376 lbf

70.024 kgf

6.867e+7 dyn

Weight on Different Celestial Bodies

Mercury:259 N

Venus:620.9 N

Earth:686.7 N

Moon:113.4 N

Mars:259.7 N

Jupiter:1735.3 N

Saturn:730.8 N

Uranus:608.3 N

Neptune:780.5 N

Pluto:43.4 N

Sun:19180 N

How to Use the Weight Calculator

Step-by-Step Instructions

Select your calculation method from the dropdown menu
Enter the mass value and select the appropriate unit
Choose gravitational acceleration or celestial body
View the calculated weight and additional information
Compare weights across different planets and conditions

Calculation Methods

Mass & Gravity: Weight = Mass × Gravity
Celestial Bodies: Compare weights on different planets
Unit Conversion: Convert between weight units
Apparent Weight: Weight with additional acceleration

Physics Formulas and Concepts

Fundamental Formulas

Weight Formula:
W = m × g
Where W = weight, m = mass, g = gravitational acceleration

Apparent Weight:
W_apparent = m × (g ± a)
Where a = additional acceleration

Newton's Second Law:
F = m × a
Weight is a special case where F = W and a = g

Key Concepts

Mass vs Weight: Mass is constant, weight varies with gravity.

Gravitational Field: Different celestial bodies have different gravitational accelerations.

Apparent Weight: The weight you feel when experiencing additional acceleration (elevators, vehicles).

Weightlessness: Occurs when apparent weight becomes zero (free fall).

Example Calculations

Example 1: Person on Earth

Given: Mass = 70 kg

Earth's gravity: 9.81 m/s²

Calculation: W = 70 × 9.81 = 686.7 N

Result: A 70 kg person weighs 686.7 Newtons on Earth

Example 2: Same Person on Moon

Given: Mass = 70 kg (unchanged)

Moon's gravity: 1.62 m/s²

Calculation: W = 70 × 1.62 = 113.4 N

Result: The same person weighs only 113.4 Newtons on the Moon

Frequently Asked Questions

Why do I weigh less on the Moon?

The Moon has much weaker gravity (1.62 m/s²) compared to Earth (9.81 m/s²). Since weight = mass × gravity, your weight decreases proportionally while your mass stays the same.

What is apparent weight?

Apparent weight is the force you feel pressing against a surface. It can differ from your true weight when you're accelerating, like in an elevator or during vehicle acceleration.

Why do astronauts float in space?

Astronauts in orbit are in continuous free fall around Earth. Their apparent weight becomes zero because they and their spacecraft are accelerating toward Earth at the same rate.

How accurate are these calculations?

The calculations use standard gravitational values. Actual gravity can vary slightly due to altitude, latitude, and local geological features, but these variations are typically less than 1%.