Weightnote · Habits

Are Bathroom Scales Accurate? (And Does It Matter?)

Guide · 3 min read

Your scale says 74.2, the gym's says 75.1, the doctor's says something else again. Which one is right? Here's the surprisingly liberating answer: for tracking, it barely matters.

Quick answer: Home scales are typically within about ±0.5 kg, and different scales rarely agree. For tracking it doesn't matter: use one scale, same spot, same time — consistency beats accuracy, because the trend cancels out any fixed offset.

How accurate are home scales?

Decent digital bathroom scales are typically accurate to within about half a kilo, and precise to 0.1 kg steps. Cheap or old load cells drift; batteries fade; and every scale reads slightly differently from the next.

What throws readings off

Why consistency beats accuracy

Suppose your scale reads 0.4 kg heavy — every single day. Your absolute weight is slightly wrong, but your changes are exactly right, and changes are the entire point of tracking. A consistent scale with a fixed error gives you a perfect trend.

The practical rules

One scale, hard floor, same spot, same time of day. Never 'verify' on a second scale — you'll just import someone else's offset into your data and call it a gain.

Common questions

Why do two scales show different weights?
Each scale has its own calibration offset, and floors, placement and even temperature shift readings. A 0.5–1 kg disagreement between scales is completely normal and says nothing about your body.
Why does my scale give a different weight if I step on twice?
Load cells need to settle. Step on once, wait for the reading to lock, and use that. If repeat readings vary a lot, put the scale on hard floor in a fixed spot — or replace it.
Do I need an expensive scale to track weight?
No. Any consistent scale works, because tracking cares about change, not absolute truth. Spend the money on nothing — consistency is free.
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