About

In structural engineering and rigging, loads are often specified in Kilonewtons (Force), while materials and counterweights are measured in Kilograms (Mass). This converter bridges the gap between static force and equivalent mass using Newton's Second Law.

It is critical to note that this conversion is dependent on the local gravitational field. By default, this tool applies standard Earth gravity (g ≈ 9.81 m/s²). However, for high-precision laboratory work or theoretical calculations in non-standard environments, the gravity parameter can be adjusted. This distinction is vital for safety factors in crane operations and load-bearing structure design.

Formulas

The conversion derives from Newton's Second Law: F = ma. To find mass from force (weight), we rearrange the formula:

m = F × 1000g

Where:

m is Mass in Kilograms (kg).
F is Force in Kilonewtons (kN).
g is gravitational acceleration (default 9.80665 m/s²).
1000 converts kN to Newtons.

Reference Data

Environment	Gravity (m/s²)	10 kN converts to approx Mass
Earth (Standard)	9.807	1,019.7 kg
Earth (Equator)	9.780	1,022.5 kg
Earth (Poles)	9.832	1,017.1 kg
Moon	1.625	6,153.8 kg
Mars	3.721	2,687.4 kg
Jupiter	24.790	403.4 kg
Sun	274.00	36.5 kg

Frequently Asked Questions

Multiplying by 100 is a rough "rule of thumb" (assuming g=10) that leads to a ~2% error. For professional engineering, you must divide by 9.80665, which results in a factor of approx 101.97. This tool uses the precise constant.

Mass is constant everywhere, but Force (Weight) depends on gravity. A 100kg object exerts ~0.98 kN on Earth but only ~0.16 kN on the Moon. To convert back from Force to Mass, you must know the gravity that created the force.

This tool calculates "Equivalent Static Mass". For dynamic loads involving acceleration (like a falling object), additional physics calculations regarding impact force are required.

The tool defaults to standard gravity (gn) defined by ISO 80000-3 as exactly 9.80665 m/s².