LOW CARBON TECLUX CO., LTD

LOW CARBON TECLUX

LED commercial lighting manufacturer since 2010 — factory direct OEM/ODM for EU & AU market, lighting calculator below

LED Lighting Calculator for Warehouses and Retail Stores

This LED lighting calculator for warehouses and retail stores sizes fixture counts with the lumen method: enter target lux, room size and one luminaire's lumens, and it returns how many LED lights you need, total watts and achieved lux in seconds. It follows the same maintained-illuminance logic as the retail lighting solution for supermarket sales floors, where 500 lux must still hold on the last day of the maintenance cycle — not just on day one. The worked example below runs on the FORT-A DALI linear high bay for warehouses at 170 lm/W.

Presets follow EN 12464-1 maintained values, so a warehouse aisle starts at 200 lux while a checkout counter starts at 500. If daylight already covers part of the task, pair the result with daylight dimming that holds 500 lux instead of over-installing fixtures. After sizing, pull the project IES files in the download library for Dialux verification — this tool replaces the spreadsheet, not the lighting study. Everything here also fits the wider lighting solution hub for project planning.

LED lighting calculator for warehouse aisles with linear high bays
Racking aisles lit by linear high bays sized with the LED lighting calculator below.

Lumen-Method Calculator

N = (E x A) / (F x CU x MF) — maintained lux, rounded up to whole fixtures

Room index K = — Enter dimensions and height to see the CU hint.

0

Fixtures needed

0

Total lumens (lm)

0

Total power (W)

0

Achieved lux

Planning estimate only — verify layout, uniformity and glare in Dialux before ordering.

The Formula Behind the Result

The calculator uses the lumen method taught in lighting design courses worldwide: N = (E x A) / (F x CU x MF), where E is target maintained lux, A is floor area in m², F is lumens per luminaire, CU is the share of light reaching the work plane, and MF discounts dirt and lumen depreciation. The result always rounds up — half a luminaire cannot be installed — so achieved lux usually lands slightly above target.

Two factors carry most of the engineering. CU runs about 0.3 in tall narrow rooms with dark finishes and up to 0.7 in wide rooms with reflective ceilings; without manufacturer UF tables, 0.5 to 0.6 is a reasonable default. MF runs 0.8 to 0.9 in clean offices but drops to 0.6 in dusty industrial halls. Designing to initial lumens without MF is the classic mistake: the room passes on day one and fails the standard a year later.

MF itself is a product of three IESNA handbook factors: lamp lumen depreciation (LLD), luminaire dirt depreciation (LDD) and room surface dirt depreciation (RSDD). A typical warehouse at MF 0.7 could mean LLD 0.9 with LDD and RSDD near 0.88 each after a 3-year cleaning cycle — which is why dirty sites must start with more fixtures, not brighter ones.

Maintenance Factor by Environment

Match MF to dirt load and cleaning cycle, not to optimism

EnvironmentMFCleaning cycle
Clean office, classroom0.85–0.903 years
Clean warehouse, retail0.80–0.853 years
General production, workshop0.703 years
Heavy industry, dusty hall0.602 years
Food cleanroom0.853 years

Room Index, CU and Spacing

CU is read from manufacturer tables against the room index K = (L x W) / (Hm x (L + W)), where Hm is mounting height above the work plane — the calculator above computes K live and hints the CU band. Tall narrow rooms (K below 1) trap light on walls and need a low CU; wide rooms (K above 2) return more light to the plane. After the count, lay fixtures on a grid inside their spacing-to-mounting-height ratio — typically 1.0 to 1.5 — with the first row half a pitch from the wall, or average lux will be right while uniformity fails.

EN 12464-1 Lux Table: Commercial Spaces

Maintained Em values buyers actually get asked for in EU tenders

SpaceEm (lux)Uniformity UoCRI Ra
Sales area3000.4080
Supermarket sales floor5000.4080
Checkout / till5000.6080
Office desk work5000.6080
Meeting room5000.6080
Classroom3000.6080
Restaurant dining2000.4080
Corridor / circulation1000.4040

EN 12464-1 Lux Table: Industrial Spaces

Warehouse and factory values with maintenance factors that match

SpaceEm (lux)MF guideCRI Ra
General storage1000.8060
Picking / sorting aisles2000.7560
Loading / docking1500.7560
Order packing3000.7080
Machine work3000.7080
Fine assembly7500.7080
Quality control7500.7080
Precision electronics10000.7090
Indoor parking750.8040

Worked Example: 2400 m² Picking Warehouse

A 60 by 40 metre picking warehouse needs 200 lux maintained. The pick is a 150 W linear high bay delivering 25500 lm at 170 lm/W, with CU 0.6 and MF 0.7 for a dusty hall: total lumens = (200 x 2400) / (0.6 x 0.7) = 1142857 lm, divided by 25500 lm gives 44.8 → 45 fixtures, 6750 W total, 200.8 lux achieved. Type the same numbers into the calculator above and it returns the same answer.

Warehouse racking overview lit by calculated linear high bays
High-angle view of the racking aisles behind the 45-fixture warehouse example.

Where the Numbers Come From

The lux tables above follow EN 12464-1:2021 maintained values, cross-checked across three independent published tables because the standard text itself is paywalled. The calculation method is the IES zonal cavity (lumen) method, stated for maintained illuminance as N = (E x A) / (F x CU x MF) in Lighting Analysts' Room Estimator concepts guide, which also documents the empty-room and uniformity limits honestly. Final verification belongs in DIALux evo, free lighting design software from DIAL GmbH, the worldwide standard for point-by-point proof.

Lighting Calculator FAQ

Lux targets, CU and MF, and Dialux answers for buyers

About 40 fixtures of 25500 lm at CU 0.6 and MF 0.7 — (200 x 2000) / (0.42) = 952381 lm, divided by 25500 lm is 37.4, rounded up to 38, plus a layout grid that usually pushes the count to 40. Picking aisles use 200 lux per EN 12464-1; storage zones beside them only need 100.

Yes for the final layout — this tool sizes quantity, Dialux proves uniformity and glare. The lumen method predicts average lux only; it says nothing about dark corners, UGR or spacing-to-height ratio. Size here in seconds, then verify with IES files before ordering.

Start with CU 0.6 and MF 0.8, then adjust for dirt — clean offices run MF 0.85 to 0.9, general warehouses 0.7 to 0.8, dusty heavy industry 0.6. CU below 0.5 means most light never reaches the work plane; fix reflectances or optics before adding fixtures.

Because 500 lux is maintained, not initial — new rooms must start higher. Initial lux equals maintained lux divided by MF, so 500 / 0.8 = 625 on day one. If a handover reads exactly 500 with MF 0.8, the room will fall below standard within the first cleaning cycle.

Compare lumens, not watts: one 25500 lm LED bay replaces about three 8000 lm twin-tube battens. Add the old fixtures' total lumens, divide by the LED luminaire's lumens, and round up per row so existing circuits stay balanced. Retrofit counts still need the same CU and MF correction.

Lux follows the visual task, not the room size — corridors need orientation light for safe movement, checkouts need reading light for prices, labels and cash. EN 12464-1 sets 500 lux wherever errors cost money and 100 lux where only circulation happens.

Keep spacing within 1.0 to 1.5 times the mounting height above the work plane — beyond that, pools separate and uniformity drops below 0.4 even when average lux passes. Start the first row half a pitch from the wall, then prove the grid point-by-point in Dialux.

Send Message

Fill out the form and we will get back to you as soon as possible