Formula
- Use the units shown beside each field.
- Results update automatically whenever you change an input.
- Displayed values use up to four decimal places, or scientific notation for very small or large numbers. Calculations use standard floating-point arithmetic; exact integer and fraction tools identify their own precision rules.
- Ideal Euclidean geometry. Use one consistent length unit. Measurements and derived quantities use floating-point arithmetic. Both objects must be vertical, on level ground, and measured at the same solar angle.
Example Calculation
- Reference object height: 2 units
- Reference shadow length: 3 units
- Target shadow length: 12 units
A 2-unit reference casts a 3-unit shadow; a 12-unit shadow gives height 8.
Frequently asked questions
How do I use this calculator?
Enter reference object height, reference shadow length, target shadow length. The result updates automatically. Use Reset to restore the example values.
What method does it use?
target height=reference height × target shadow/reference shadow. Ideal Euclidean geometry. Use one consistent length unit. Measurements and derived quantities use floating-point arithmetic. Both objects must be vertical, on level ground, and measured at the same solar angle.
Why might a rounded result differ?
The calculation keeps full numeric precision internally, then rounds the displayed result. Rounding intermediate steps by hand can produce a slightly different answer.
Are my inputs saved online?
No. This calculator processes your inputs in your browser. A recently used list stores only calculator names on this device, not your entered values.
Check the assumptions and units before using this result. Read about calculation methods.