# Weighing machine, kg vs. N

When I stand on a weighing machine and it shows me the number 75 , is it my mass in Kg or the Normal Force due to gravity in N

• Must be in kg, unless you are an infant. 75 N ~ 17 lbs. – Zack Hutchens May 21 at 19:51
• Hahahaha! The 17 lb infant who can type on this forum, and make sense in doing so, is a genius that I would pay to meet! – David White May 21 at 23:44

It measures force, but is calibrated in mass via known proportionality $$F[N]=m[kg]\cdot g$$
where $$g=9.81 ~\mathrm{kg\cdot m^{-2}}$$
Sometimes kg is used as a unit of force. The kg force is defined as the force required to impart an acceleration of 9.8 m/s^2 on an object of mass 1 kg. Therefore, 1 kg force is the same as 9.8 N. If force is expressed in kg, then Newton's law expressed in terms of kg force becomes $$F=\frac{ma}{9.8}$$where m is measured in kg mass, and a is measured in m/s^2.