Plan efficient grow lighting with accurate density checks. Track fixtures, drivers, dimming, and add-ons easily. See instant compliance, then download reports for records today.
| Area | Fixtures | W/Fixture | Driver | Diversity | Control % | Installed Power | Installed LPD |
|---|---|---|---|---|---|---|---|
| 50.00 m² | 12 | 40 W | 1.00 | 1.00 | 10% | 480.00 W | 9.6000 W/m² |
| 600.00 ft² | 8 | 100 W | 1.05 | 0.90 | 20% | 756.00 W | 1.2600 W/ft² |
These examples illustrate typical conversions and how drivers, diversity, and controls affect planning metrics.
Installed Watts = (Fixtures × Watts/Fixture × Driver Factor × Diversity Factor) + Additional Watts
Controlled Watts = Installed Watts × (1 − Control Reduction ÷ 100)
Lighting Power Density (LPD) = Watts ÷ Area
Lighting power density (LPD) is installed lighting watts divided by the growing area. In greenhouses and indoor rooms, LPD helps balance crop light goals with electrical capacity, heat load, and operating cost. A higher LPD can raise room temperatures and cooling demand, while a lower LPD may require longer runtime or better fixture placement.
Use the true lit area, not the full building footprint, and keep units consistent. The calculator totals fixture watts, applies a driver factor to reflect real draw, and a diversity factor to represent simultaneous operation. Add “additional watts” for supplemental bars or task lighting. Controls are represented as a reduction percentage for planning.
Installed LPD represents the maximum density when all fixtures can run. Controlled LPD estimates expected demand after dimming schedules, sensors, or staged zones. For a limit check, compare installed LPD to the target, and use controlled LPD for utility forecasting. Conversions are shown for W/m² and W/ft² using 1 m² = 10.7639 ft².
After LPD is known, multiply installed watts by runtime hours to estimate daily kWh, then map that against breaker capacity and service limits. Higher watts per square area increases sensible heat, often requiring ventilation or cooling. Dimming, zoning, and improved uniformity can lower peak demand while keeping consistent coverage.
Use the example scenarios to verify inputs: 50.00 m² with 12 fixtures at 40 W yields 480 W and 9.6000 W/m². A 600 ft² zone with 8 fixtures at 100 W, driver 1.05, and diversity 0.90 yields 756 W and 1.2600 W/ft². If results exceed targets, consider zoning, higher‑efficacy fixtures, or control strategies and re‑run the report during upgrades.
It depends on crop goals, fixture efficacy, and heat limits. Use LPD as an electrical density check, then confirm canopy performance with light measurements and plant response.
Measured draw is best. If you only have nameplate values, keep the driver factor at 1.00 and document assumptions in Notes for future verification.
It adjusts fixture wattage to reflect real power draw, including driver behavior and operating conditions. Small differences can change LPD noticeably on large growing areas.
Set it to the fraction of fixtures expected to run at once. Zoned rooms, staggered schedules, and backup fixtures often justify values below 1.00.
Controls influence the controlled LPD planning metric. For a strict limit, compare installed LPD to your target because it reflects available connected lighting load.
Different standards and teams use different units. Showing both prevents conversion errors and makes it easier to share reports with auditors and contractors.
Reduce connected watts through zoning, dimming, fixture selection, or layout changes. Recalculate after each change, then export a new report for documentation.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.