Actual Size from a Scale Bar Calculator
🔬 Cells & microscopy. Use the Actual size from a scale bar formula to find real size, measured length on the image, scale bar length on the image, value written on the scale bar: pick the value you want, type the others, and the answer updates as you go.
Pick the ○ next to the value you want to find, fill in the others, and it solves as you type.
What each letter means
| Quantity | Unit |
|---|---|
| Real size | µm |
| Measured length on the image | mm |
| Scale bar length on the image | mm |
| Value written on the scale bar | µm |
Worked example
Find the real size when Measured length on the image = 50 mm, Scale bar length on the image = 20 mm, Value written on the scale bar = 10 µm.
Using real size = (measured length)/(scale bar length) × scale bar value: Real size = 25 µm.
Frequently asked questions
What is the formula for Actual size from a scale bar?
real size = (measured length)/(scale bar length) × scale bar value.
What do the letters stand for, and what units are used?
Real size in µm, Measured length on the image in mm, Scale bar length on the image in mm, Value written on the scale bar in µm.
How do you calculate real size?
Put the values into real size = (measured length)/(scale bar length) × scale bar value. For example, with Measured length on the image = 50 mm, Scale bar length on the image = 20 mm, Value written on the scale bar = 10 µm, real size = 25 µm.
Can I solve for a different value?
Yes. In the calculator above, pick the circle next to any value (real size, measured length on the image, scale bar length on the image, value written on the scale bar) and fill in the others: it rearranges the formula for you.
