Calculators
Five tools for daily radiation-safety work. Pure-client, no data leaves your browser.
Dose Equivalent
Convert between sievert and historical/US units.
—
1 Sv = 100 rem; 1 Gy = 100 rad; Sv↔Gy assumes Q=1 (γ, β, X-ray).
Activity
Convert between becquerel and curie.
—
1 Ci = 3.7 × 10¹⁰ Bq (exactly, by definition)
Half-life Decay
Activity remaining after elapsed time. N(t) = N₀ · e−λt, λ = ln2 / t½.
—
defaults shown: I-131, t½ = 8.02 d, 30 d elapsed
Shielding Thickness
Required thickness to attenuate γ to target fraction. I/I₀ = e−µx; HVL = ln2/µ.
—
Half-value layers from NIST XCOM standard tables; broad-beam, narrow-spectrum approx — recheck for design work.
Energy / Wavelength
Photon energy ⇄ wavelength ⇄ frequency. Useful for laser, X-ray, RF work.
—
E = hν = hc/λ. h = 4.135667696 × 10⁻¹⁵ eV·s; c = 299792458 m/s.
Formulas + constants pinned for traceability. Submit a suggestion if a tool is missing or wrong.