Lighting & Spectrum

PPFD Calculator

PPFD mapping, heatmaps, and layout analysis for fixture planning.

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What it does

A PPFD heat map for a rectangular room with a grid of identical fixtures. It plots photosynthetic photon flux density at canopy level and reports average, maximum and minimum PPFD, uniformity and DLI.

When to use it

Use it to see how fixture count, PPF, beam angle and mounting height change PPFD levels and uniformity across the canopy. The on-screen report says the estimate should be checked with quantum-sensor field measurements before commissioning.

How it calculates

Fixtures are spaced evenly in a grid across the room. Each fixture is modeled as a point source with a cos² beam profile, a soft edge at the beam angle, and a surface-cosine and inverse-square falloff.
PPFD is summed over a canopy grid of 20 to 80 cells per side. Feet are converted to meters before the calculation.
Uniformity is minimum PPFD divided by average PPFD (min/avg).
DLI = average PPFD × photoperiod × 0.0036

What you enter

PPF(μmol/s)
Fixture Count
Wattage per Fixture(W)
Beam Angle(°, 60–150)
Width(ft)
Length(ft)
Mounting Height(ft)
Canopy Height(ft)
Photoperiod(hours)

What you get

PPFD Distribution Map(μmol/m²/s)
Average PPFD(μmol/m²/s)
Max PPFD(μmol/m²/s)
Min PPFD(μmol/m²/s)
Uniformity(min/avg ratio)
DLI(mol/m²/day)
Power Density(W/ft²)

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