Step 00 — Free calculator
What is your lighting costing you?
A free session with the Earthlight model. Pick your building, see the recommended circadian schedule and what it does to exposure at the eye, and put a defensible range on what better light is worth — then take the report with you. No sign-up to explore; an email for the download.
01
Your building
The schedule and exposure model below come from the Earthlight app's presets for this environment.
02
Your light, corrected
The recommended 24-hour schedule for a office environment — and what it does to circadian exposure at the eye.
Drag across the day to scrub the schedule.
At 9am
100%
Light intensity
6000K
Color temperature · Cool Daylight
~90%
of the circadian gap closed across the occupied day, vs static lighting*
7.5 / 10 hrs
occupied hours at or above the 250 target — typical static lighting reaches it for 0
*Modeled estimate, not a site measurement. Baseline: Static electric lighting at one intensity and color all day: about 180 photopic lux at the eye at 4000 K, ≈128 melanopic EDI — beneath the daytime target for every occupied hour.
03
Your number
The app's ROI model, unabridged: every figure computed three ways — conservative, base, and optimistic.
Your organization
Modeled annual savings
$332,550 – $1,153,300
base case $724,250 · payback 0.2 yr
- Productivity gain$520,000
- Reduced sick days$52,000
- Reduced turnover$146,250
- Energy savings$6,000
Assumptions version 2026-06-poc-v2 — identical to the Earthlight app. Every band is published in the report below.
04
Your report
A personalized summary of everything above — inputs, the three-case financial model, the recommended schedule, and the research behind it.
An estimate opens the conversation. Measurement wins it.
Step 01 replaces every assumption in your report with your building’s measured light — the version that survives procurement.