Force Reference Sheet

Metric (SI)

• 1 newton (N) = 1 kg·m/s²
• 1 kilonewton (kN) = 1,000 N
• 1 meganewton (MN) = 1,000,000 N

Common non-SI units

• 1 pound-force (lbf) ≈ 4.448221615 N
• 1 kilogram-force (kgf) ≈ 9.80665 N
• 1 dyne (dyn) = 1×10⁻⁵ N
• 1 ounce-force (ozf) ≈ 0.278013851 N
• 1 poundal (pdl) ≈ 0.138254954 N

Non-SI → SI

• 10 lbf ≈ 44.482216 N
• 50 kgf ≈ 490.3325 N
• 2,000 dyn = 0.02 N
• 30 ozf ≈ 8.340415 N

SI → Non-SI

• 100 N ≈ 22.4809 lbf
• 1,000 N (1 kN) ≈ 101.9716 kgf
• 5 N = 500,000 dyn
• 20 N ≈ 71.9425 ozf

Quick benchmarks

• Apple weight (~100 g): ≈ 0.98 N
• A brick (~2.2 kg): ≈ 21.6 N
• Seat belt tension in hard braking: hundreds of N
• Bolt clamping from tightening can reach several kN

Table: factors to newtons (N)