Calculate with the assumptions in view.
Eight local calculators for preliminary engineering estimates. Inputs stay in your browser; outputs are not a laboratory measurement or safety approval.
Luminous efficacy
Compare measured luminous flux with the electrical input at the same operating point.
ηv = Φv / PeOpen calculator CALCULATORLow-voltage LED resistor
Estimate a series resistor at one DC operating point.
R = (Vs − n × Vf) / I; Pr = I²ROpen calculator CALCULATORThermal budget
Estimate a steady-state junction temperature and the remaining heat-sink budget.
Pheat = Pe − Popt; Tj = Ta + Pheat × (Rjc + Rcs + Rsa)Open calculator CALCULATORBeam diameter
Estimate the width defined by a stated full beam angle at a distance.
D = 2d × tan(θ / 2)Open calculator CALCULATORPoint-source illuminance
Estimate far-field illuminance using luminous intensity and incidence angle.
E = I × cos(α) / d²Open calculator CALCULATORDaily light integral
Calculate DLI from measured PPFD and a constant lighting schedule.
DLI = PPFD × hours × 0.0036Open calculator CALCULATORLED display pixel planning
Estimate whole pixels from physical width, height and pixel pitch.
Nx = floor(W / p); Ny = floor(H / p)Open calculator CALCULATORLighting energy cost
Estimate input energy and cost for a constant daily operating schedule.
kWh = W × quantity × hours/day × days / 1000Open calculator Need a product shortlist?
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