How to use the thin lens equation calculator
Find image distance and magnification for a lens. Enter focal length, object distance in the fields above; the image distance, magnification, image type are computed instantly and plotted on the chart so you can see how the answer changes.
Formula
Variables
- f — Focal length (cm)
- dobj — Object distance (cm)
Worked example
With focal length = 10 cm, object distance = 30 cm, the calculator gives image distance ≈ 15 cm; magnification ≈ -0.5; image type ≈ Real, inverted.
Frequently asked questions
What is the formula for the thin lens equation calculation?
Image distance (cm) = 1 / (1 / f-1 / dobj). Magnification = -[Image distance] / dobj. Image type = [Image distance]>0?"Real, inverted":"Virtual, upright". Here f is focal length (cm), dobj is object distance (cm).
What inputs do I need for the thin lens equation calculator?
You need focal length in cm, object distance in cm. Each field is pre-filled with a typical example so you can see how the result responds as you edit the numbers.
How do I use this calculator?
Type values into the input fields. Results and the chart update instantly. Use Reset to restore the example values, Copy results to paste them elsewhere, or Share to copy a link that preserves your inputs.
Is the result exact?
Calculations use standard formulas and double-precision arithmetic, then display about seven significant figures. Real-world measurements carry uncertainty, so treat results as estimates unless your inputs are exact.