Emergency Lighting Lux and Luminaire Count Calculator
Required illuminance by area type under EN 1838, an estimated luminaire count from the lumen method, and the spacing limit that keeps it uniform.
Calculator
From the type of area to the minimum illuminance, an estimated luminaire count and the maximum spacing that keeps it uniform.
Result
The calculation runs entirely in your browser; nothing you type is sent to our servers. Only if you press “Turn this into a quote request” is the result written to your browser’s session storage, so it can be carried into the quote form.
Worked example
Opened with its default case — Type of area: Escape route / corridor — at least 1 lx · Width (m): 2 · Length (m): 30 — the calculator returns the figures below. They are written out here so the output is readable without running JavaScript: in print, with scripts disabled, or by a search engine.
| Input | Value |
|---|---|
| Type of area | Escape route / corridor — at least 1 lx |
| Width (m) | 2 |
| Length (m) | 30 |
| Luminaire mounting height (m) | 3 |
| Luminaire output in emergency mode (lm) | 120 |
| Utilisation factor (UF) | 0.4 |
| Maintenance factor (MF) | 0.8 |
| Normal illuminance (lx) | 300 |
| Occupancy (people) | 50 |
| Mandatory points (extra luminaires) | 0 |
| Result | Value |
|---|---|
| Required illuminance | 1 lx |
| Area | 60 m² |
| Count by the lumen method | 2 units |
| Minimum count for uniformity | 3 units |
| Estimated luminaire count | 3 units |
| Maximum spacing | 12 m |
| Required duration | At least 1 h under EN 1838; national rules may require longer |
| Rule | At least 1 lx on the centre line of the escape route, at floor level |
Change any field above and the calculator recomputes; this table is the default case only.
How many lux and how many luminaires does emergency lighting need?
The type of area sets the level. Under EN 1838 an escape route needs at least 1 lx on the centre line at floor level; an open (anti-panic) area of 60 m² or more needs at least 0.5 lx excluding a 0.5 m border; a high risk task area needs 10% of the normal maintained illuminance and never less than 15 lx. The luminaire count then comes from two independent checks and you take the larger: the lumen method (count = required lux × area ÷ (emergency lumens × UF × MF)) and a geometric limit — our planning rule keeps spacing to about four times the mounting height (not an EN 1838 requirement; the manufacturer’s spacing table governs), or the average is met while dark patches remain. On duration, EN 1838 sets at least one hour for escape lighting; national regulation may require longer, so this calculator prints only that minimum. Values follow the widely quoted 2013 edition; EN 1838:2024 has been published — check against it and the manufacturer’s photometric design.
The three levels, and where each applies
| Type of area | Minimum | Measured where | Typical location |
|---|---|---|---|
| Escape route | 1 lx | Centre line, at floor level, up to 2 m of route width | Corridors, stairs, exit routes |
| Open (anti-panic) area | 0.5 lx | Across the area excluding a 0.5 m border; applies from 60 m² | Open-plan floors, halls, large retail areas |
| High risk task area | 10% of the normal illuminance, minimum 15 lx | On the task plane | Machinery that must be shut down safely, laboratories, switchrooms |
Below 60 m², an open area falls outside the anti-panic requirement — the escape route through it still needs its own 1 lx. The three categories are not alternatives; a single floor commonly contains all three.
Emergency lumens are not normal lumens
This is the mistake that can make a calculation come out several times too optimistic. A combined (maintained) luminaire runs at full output on mains and switches to a much lower output on battery — the emergency lumen output. Some products deliver a small fraction of their mains figure in emergency mode.
Use the emergency figure from the datasheet, not the headline lumens. If the datasheet gives only a percentage, apply it to the mains output and use the result. If it gives neither, that is itself an answer about the product.
Two further factors reduce the light that actually lands on the floor. The utilisation factor accounts for what the room surfaces return — our planning range for emergency lighting is 0.3 to 0.5, with dark interiors at the bottom. The maintenance factor accounts for dirt and lumen depreciation over the maintenance cycle; we plan with 0.8 unless the manufacturer states otherwise. Leaving both at 1.0 cuts the luminaire count on paper to between a quarter and two-fifths of the planned figure (0.3–0.5 × 0.8) and fails the commissioning measurement.
Two checks, and why the larger one wins
The lumen method answers how much light. It does not answer where. A corridor lit by two very bright luminaires 30 m apart can satisfy the average and still leave the middle dark, which is precisely the part someone has to walk through.
The geometric check fixes that: keep the spacing at or below about four times the mounting height. At 3 m mounting height that is a 12 m maximum spacing, so a 30 m corridor needs at least three luminaires however bright they are. The calculator reports both counts separately and takes the larger, so you can see which one is governing.
The points a luminaire is required regardless
EN 1838 requires a luminaire at specific locations irrespective of what the lux calculation returns. These are the places where people stop, turn or need to find something:
- At each exit door intended for emergency use.
- Near stairs, so each flight receives direct light.
- At every other change of level.
- At every mandatory change of direction.
- At each corridor intersection.
- Near each final exit and outside it.
- Near each first aid post.
- Near each piece of firefighting equipment and call point.
EN 1838 takes “near” as within 2 m measured horizontally. Count these points on the plan and enter the total — the calculator adds them on top of the calculated count rather than assuming the grid happens to cover them.
Duration, testing and the logbook
EN 1838 sets at least one hour for escape lighting; how long the system must actually operate — one hour, three hours, or longer — is set by the national fire or building regulation that applies to your premises, and it often varies with occupancy and building type. This calculator therefore prints only the EN 1838 minimum; for Türkiye the required durations are listed with their legal references in our Turkish emergency lighting tool.
What is universal is that the duty does not end at installation. Emergency luminaires need periodic function testing and a longer full-duration test, with the results recorded. The practical consequence for procurement is the choice between manually tested luminaires and self-test or addressable systems: on more than a few dozen fittings, self-test can save more testing labour than it costs and produces an automatic record — compare the two on your own fitting count.
What to send us for a quote
Send the calculator output with the ceiling height, the ceiling type (suspended, concrete, exposed) and whether you want maintained or non-maintained fittings. Ceiling type decides the mounting accessory, which is the part most often missing on delivery day. We quote luminaires, exit signage, batteries, mounting kits and the test equipment as one list, delivered to site.
Frequently Asked Questions
How many lux does an escape route need?
At least 1 lx on the centre line at floor level under EN 1838, for a route up to 2 m wide. An open anti-panic area of 60 m² or more needs 0.5 lx excluding a 0.5 m border, and a high risk task area needs 10% of the normal illuminance with a floor of 15 lx.
Why is my luminaire count higher than the lumen method suggests?
Because uniformity, not average light, is often the binding constraint. Spacing beyond about four times the mounting height (our planning rule; the manufacturer’s spacing table governs) leaves dark patches between fittings even when the average is met. The calculator reports both counts and takes the larger.
What is the emergency lumen output?
The light a luminaire produces on battery, which is much lower than its mains output on a combined fitting. Using the mains figure in the calculation is the most common reason a finished installation fails its commissioning measurement.
How long must emergency lighting stay on?
That is set by the national fire or building regulation for your premises and commonly varies with occupancy. This tool deliberately does not assume a figure; check the code that applies to you, and see our Turkish tool for Türkiye’s requirements with their legal references.
Do I need a luminaire at every exit even if the lux level is met?
Yes. EN 1838 requires luminaires at defined points regardless of the calculated level — exits, stairs, changes of level and direction, corridor intersections, first aid posts and firefighting equipment. Count them and add them to the calculated total.
Are self-testing luminaires worth the extra cost?
Above a few dozen fittings, often yes — compare on your own fitting count. The saving is in the labour of monthly function tests and annual duration tests, and in producing a record automatically. Below that, manually tested fittings with a disciplined logbook are reasonable.
Related guides
Send your list — your quote is ready within 1 business day.
A list, a photo or an Excel file — whatever is easiest. On standard items most quotes go out the same business day. Custom production, imports or 50+ line lists can take longer; when they do, we tell you the timeline in writing on the day we receive the request.