Critical Angle Calculator
Compute the critical angle θ_c = arcsin(n₂/n₁) for total internal reflection.
Input Data
N1
N2
Results
41.8103°
At a glance:θ_c = arcsin(n₂/n₁) (n₁ > n₂); beyond it, total internal reflection. Complements snells-law and brewster-angle.
Formula
sinθ_c = n₂/n₁.
$$\theta_c = \arcsin\left(\frac{n_2}{n_1}\right)$$How to Use
- Enter n₁ and n₂.
- The tool returns the critical angle and TIR flag.
Case Studies
glass→air n₁=1.5, n₂=1
θ_c ≈ 41.8°.
FAQ
n₂ > n₁?
No critical angle — no TIR (and tool flags invalid).
Related Tools
References
Content review: Calculatorism Science Team. Results are for reference only; please refer to the relevant authorities for the official figures.