What an inspiring thread!

@mfalkvidd Thanks!

Since your maximum load is over a ton, then it is advisable to get a load cell with that capacity range. You can then program your application to read any weight value over 150kg up to the load cells rated output as overload.
Therefore, in a way you get to measure exactly within the range of 0kg (or depending on the offset weight) to a maximum of 150kg. Load cells with the capacity of over a ton are probably costly, but you can better improve your design to prevent such sudden force from being exerted on the chair. Maybe by incorporating a spring coupled with the load cell into your design.

Wow superb!

So many space, I jealous :)

Just click on it