Microscopy & measurement · SL/HL
Field of View Density Calculator
Enter the count and field-of-view diameter. The tool calculates field area and density.
Your values
Start with the example or enter your own values. Use a dot for decimals and e for scientific notation.
Calculated locally. No account or input upload.
Result & working
ExampleThe calculator is loading. The worked example is also shown below.
Step-by-step working
The formula
field area = π(d/2)²
density = count / field area
| Symbol | Meaning |
|---|---|
| d | Field-of-view diameter. |
| count | Objects fully counted under a stated counting rule. |
When to use this calculator
Repeat across multiple independent fields and calculate a mean if estimating tissue density.
Worked example
The page opens with these example values. The result below is pre-generated for reference.
- Diameter = 500 µm
- Area = π(d/2)² = π(500/2)² = 196349.5 µm²
- density = count/area = 36/196349.5 = 0.0001833465 µm⁻²
- Convert: 0.0001833465 µm⁻² × 10⁶ = 183.3465 mm⁻²
183.3465 mm⁻²
Common mistakes
- A single field may be unrepresentative.
- Use a consistent edge-counting rule to avoid double counting.