Load cell output: converting a mV reading to kg for a specific sensitivity and excitation
I was calibrating an industrial scale's load cell and needed to convert the raw millivolt signal into an actual weight reading — the conversion factor depends entirely on that specific cell's rated sensitivity and the ex
We write the way we argue on the bench: exact factor, one sharp trap, one worked example you can re-check.
I was calibrating an industrial scale's load cell and needed to convert the raw millivolt signal into an actual weight reading — the conversion factor depends entirely on that specific cell's rated sensitivity and the excitation voltage supplied, not a universal number.
Here is the conversion I wish I had taped to the fridge before that went sideways.
The factor that settles arguments
This is the relationship our converters use. Screenshot it if you have to — just stop re-deriving it from a half-remembered blog post.
For a 2 mV/V, 1,000 kg capacity cell at 10V excitation: full-scale output = 20 mV = 1,000 kg, so 1 mV = 50 kg
Write that line once at the top of your notes. Every later arithmetic step should point back to it instead of inventing a friendlier number mid-stream.
The mistake that keeps showing up
Reusing a mV-to-kg conversion factor from a different load cell's datasheet instead of recalculating for the specific cell's sensitivity rating and excitation voltage — these vary between cells and directly change the conversion.
I still write the unit next to every intermediate value. It looks pedantic until it catches the one swap that would have shipped wrong.
- Write down the known value in mV output (10V excitation, 2mV/V, 1,000kg cell).
- Confirm the target unit is really kg, not a similar-looking one.
- Apply the factor: For a 2 mV/V, 1,000 kg capacity cell at 10V excitation: full-scale output = 20 mV = 1,000 kg, so 1 mV = 50 kg.
- Round only at the end, to the precision your tool or spec supports.
Worked example
A load cell rated 2 mV/V sensitivity with a 1,000 kg capacity is excited at 10V, and you're reading 12 mV off the amplifier.
12 mV output (10V excitation, 2mV/V, 1,000kg cell) × 50 = 600 kg
That's 600 kg — round only to the precision your tool or spec actually needs.
If you want a second check, invert the conversion and see whether you recover the original quantity within normal rounding.
Quick reference table
| mV output (10V excitation, 2mV/V, 1,000kg cell) | Calculation | kg |
|---|---|---|
| 1 | 1 × 50 | 50 |
| 2 | 2 × 50 | 100 |
| 5 | 5 × 50 | 250 |
| 10 | 10 × 50 | 500 |
Use the table for speed once you trust the factor. Do not use it as a substitute for understanding which definition of the unit you are on.
Why the exact number matters
Industrial scale accuracy depends on correctly matching the load cell's specific sensitivity and excitation to the mV-to-weight conversion — using a generic or borrowed factor produces silently wrong weight readings.
Precision is not about showing off decimals. It is about making sure the shopping list, the machine setting, and the acceptance check are all describing the same physical quantity.
Pocket recap
Calculate the mV-per-kg factor from the specific cell's sensitivity and excitation voltage — for this example cell, 1 mV corresponds to 50 kg, so a 12 mV reading is 600 kg.
Keep the converter link nearby for the next time the same debate shows up in a group chat. Re-typing the factor from memory is how the wrong cousin of a unit sneaks back in.
Try the converters mentioned in this article
FAQ
What is the exact mV output (10V excitation, 2mV/V, 1,000kg cell) to kg factor here?+
For a 2 mV/V, 1,000 kg capacity cell at 10V excitation: full-scale output = 20 mV = 1,000 kg, so 1 mV = 50 kg
Should I round partway through the calculation?+
No — carry full precision through the multiplication and round only the final answer, to the precision your tool, gauge, or spec actually supports.
What's the single biggest mistake people make with this conversion?+
Reusing a mV-to-kg conversion factor from a different load cell's datasheet instead of recalculating for the specific cell's sensitivity rating and excitation voltage — these vary between cells and directly change the conversion.
This article was written by The Turbo Unit Converter engineering desk (Applied units & field metrology) and last reviewed on 2026-07-25 against NIST SP 811 and the BIPM SI Brochure. Read our full editorial policy.