Science calculator
Snell's Law Calculator
Calculate refraction angle at a boundary.
About the snell's law calculator
Snell's law calculator computes the refraction angle when light passes between media.
How to use this calculator
- 1
Enter refractive indices
Enter n₁ and n₂.
- 2
Enter incident angle
Enter θ₁ in degrees.
- 3
View results
See the refracted angle θ₂.
How the calculation works
n₁sin(θ₁) = n₂sin(θ₂). θ₂ = arcsin(n₁sin(θ₁)/n₂).
Example: Air(1.0)→Glass(1.5), θ₁=30°: θ₂≈19.5°.
Understanding scientific constants
Key constants used: g = 9.81 m/s² (Earth gravity), c = 299,792,458 m/s (speed of light), G = 6.674×10⁻¹¹ N·m²/kg² (gravitational constant), h = 6.626×10⁻³⁴ J·s (Planck's constant), R = 8.314 J/(mol·K) (ideal gas constant). Results assume ideal conditions — real-world measurements may vary.
Ideal vs. real-world conditions
Most physics calculators assume ideal conditions: no air resistance, perfect vacuums, uniform gravity. Real-world results will differ due to friction, air resistance, temperature variations, and measurement uncertainty. Use these tools for learning and estimation, not precision engineering.
Important limitations
This tool provides a mathematical estimate based only on the values entered. It does not account for regulations, taxes, lender fees, market conditions, or individual circumstances. Results are for planning purposes only — consult a qualified professional for regulated, medical, financial, or construction decisions.
Frequently asked questions about snell's law calculator
How accurate is the snells law calculator?+
The calculation follows the displayed formula and retains full numeric precision before formatting the result.
Can I use the result professionally?+
Use it as a planning estimate. Confirm regulated, medical, financial, or construction decisions with a qualified professional.