Runway Edge Light Spacing & Quantity

The full engineering-grade edge-light engine — station generation, per-side and total quantity, lateral offset geometry, threshold/runway-end reference logic, end-specific instrument-approach caution-zone colour, and existing-installation compliance, in one tool.

About this calculator

Calculators #01/#02 give a spacing figure and a nominal quantity. This calculator generates the actual station-by-station position schedule the spacing figure implies — chainage, left/right fixture, and directional colour at every position — referenced to the threshold/runway-end starting point as ICAO and FAA require, with the ICAO 60 m and FAA 200 ft (60.96 m) maximum-interval criteria kept as separate, selectable values rather than treated as identical.

Runway & Standard

Design Standard

Rule note

ICAO — uniform longitudinal interval not exceeding 60 m. FAA AC 150/5340-30J — not exceeding 200 ft (60.96 m). These are kept as distinct values, not treated as equal.

Input / Output Units

Applies to runway length, width, offset and spacing fields below.

Runway Length

Rule note

Full physical runway length, threshold/runway-end to threshold/runway-end. Edge lights run this full length regardless of any threshold displacement — see the threshold section below.

Runway Width

Rule note

Full-strength pavement width designated for runway use — used for the edge-light-row lateral geometry below.

Runway Type

Rule note

Under ICAO this selection sets S_max (100 m visual, 60 m instrument); under FAA it does not change the spacing maximum. The caution-zone colour logic below is driven independently by the per-threshold instrument-approach setting, since one end of an instrument runway can be non-instrument.

Approach Category

Rule note

Documentation only — edge-light longitudinal spacing does not vary by approach category in this engine. Threshold-light geometry by category is handled in Calculator #02 / #05.

Jet Aircraft Operation

Rule note

Sets the planning default edge-light lateral offset (3.0 m jet, 0.6 m non-jet) — confirm against AC 150/5340-30J and the approved layout.

Threshold & Runway-End Reference

Rule note

Station chainage is generated from the Threshold A / Runway-End A reference point, per the FAA design rule that threshold/runway-end lights are the starting reference for edge-light spacing. Displacement affects the landing-threshold reference used for threshold lighting (Calculators #02 / #05) — not the edge-light chainage or the caution-zone reference here, both of which run against the full physical runway length.

Threshold A displaced from physical runway end

Threshold A — Instrument Approach

Rule note

Governs whether the yellow caution zone is shown to aircraft approaching Threshold A. The zone itself lies at the far (B) end of the runway. Runway ends can differ — do not assume both ends match the overall runway type.

Threshold B displaced from physical runway end

Threshold B — Instrument Approach

Rule note

Governs whether the yellow caution zone is shown to aircraft approaching Threshold B. The zone itself lies at the far (A) end of the runway.

THRESHOLD / RUNWAY END A (chainage 0) │ ▼ EDGE LIGHT (Station 1) │ S ▼ EDGE LIGHT (Station 2) │ S ▼ ⋮ │ ▼ EDGE LIGHT (Station N+1) │ ▼ THRESHOLD / RUNWAY END B (chainage L)

Edge-Light Lateral Geometry

Edge-Light Lateral Offset (D_E)

Rule note

FAA: 0.6 m ≤ D_E ≤ 3.0 m from the edge of full-strength pavement, with 3.0 m (jet) / 0.6 m (non-jet) pre-set as a planning default — confirm against the AC and approved layout. ICAO: on the runway edge or up to 3 m outside it.

Nominal Design Spacing (S_design)

Rule note

The project/design spacing to select positions from. The engine verifies the resulting actual spacing S_actual against the applicable S_max — it does not use S_max itself as the design value.

Display & Precision

Rule note

Output unit and decimal precision for all calculated values and the station schedule.

Report details

Project Name (for report)

Runway Designation (for report)

Quantity schedule

Edge-Light Quantity Schedule

Component	Calculation Basis	Quantity
Edge lights — left side	Generated positions, chainage 0 → L	—
Edge lights — right side	Generated positions, chainage 0 → L	—
Total physical fixtures		—

Positions at chainage 0 and chainage L coincide with the Threshold/Runway-End reference points. Where a separate runway-end or threshold fitting is provided at that location (see Calculator #02 / #05), treat it as a distinct fixture/function under that calculator's shared-fixture logic — not as an additional edge light here.

Station schedule

Rule note

Generated positions, not a formula shortcut — the final count follows from this table rather than an assumed N + 1.

Build-up

Edge Offset (D_E)

—

Distance Between Edge-Light Rows (W_light)

—

Applicable Maximum Spacing (S_max)

—

Design Intervals (N)

—

Actual Spacing (S_actual)

—

Positions per Side

—

Caution Zone — Seen from A (B end)

—

Caution Zone — Seen from B (A end)

—

Left/Right Symmetry

PASS

Both rows share D_E and the same station set by construction.

Calculator #07 | Rev. 1.4 | 26 Oct 2026

Engineering reference tool. Final design shall be verified against the applicable approved airport lighting layout and governing standard.

Method & Reference

How This Calculator Works

FAA AC 150/5340-30J specifies that runway-edge lights are parallel to the runway centreline, 0.6–3 m from the edge of full-strength pavement, uniformly spaced and symmetrical, with longitudinal spacing not exceeding 200 ft (≈ 60.96 m); threshold/runway-end lights are the starting reference points for the spacing calculation.

Edge-light lateral position

0.6 m ≤ D_E ≤ 3.0 m

Measured from the edge of the full-strength pavement designated for runway use. 3.0 m (jet) / 0.6 m (non-jet) is pre-set as a planning default — this calculator applies it automatically and flags any custom entry outside the 0.6–3.0 m range.

Symmetrical edge-light rows

The two rows must be parallel to the centreline, uniformly spaced, symmetrical about the centreline, with opposite lights connected by a transverse line perpendicular to the centreline (D_L ≈ D_R, S_L ≈ S_R). Because this engine derives both rows from a single D_E and a single station set, that symmetry holds by construction rather than by a separate check.

Engineering quantity formula

For usable longitudinal edge-light length L and selected design spacing S_design:

N = ⌈ L / S_design ⌉ → S_actual = L / N → S_actual ≤ S_max

N intervals produce N + 1 generated positions per side — the calculator builds the actual station array (chainage 0 to L) rather than assuming this count from a formula alone, since the final figure depends on the endpoint/reference convention in use.

Threshold/runway-end reference architecture

Station chainage is generated from the Threshold/Runway-End A reference point, per the FAA design rule. Where a threshold is displaced from the physical runway end, two references exist: the physical runway end (used for runway-end lighting) and the landing threshold (used for threshold/approach geometry, handled in Calculators #02 and #05). This calculator's edge-light chainage and caution-zone reference always use the physical runway-length reference, independent of any displacement.

Caution-zone colour

For MIRL/HIRL, runway edge lights are white; in the caution zone, yellow replaces white — seen facing the instrument approach threshold, white in the opposite direction:

FAA: L_caution = min(2000 ft, L / 2)
ICAO Annex 14: L_caution = min(600 m, L / 3)

The zone lies at the far end from the instrument approach threshold (the rollout end), so an instrument approach to A gives yellow lights near B as seen from A. Applied independently to each approach, since an instrument approach can exist at one runway end and not the other. This calculator never applies the yellow caution zone to both directions automatically — it is driven by the per-threshold instrument-approach setting above.

Existing-installation compliance

For measured positions x_i, achieved spacing S_i = x_i − x_i−1 is checked against S_max (🟢 PASS / 🔴 FAIL), and reported as a measured value rather than PASS/FAIL alone. Cumulative deviation D_i = x_actual,i − x_design,i is also reported, since individually acceptable intervals can still hide a growing positional drift along the runway.

ICAO vs. FAA maximum spacing

Standard	S_max
ICAO Annex 14	60 m (instrument) / 100 m (non-instrument)
FAA AC 150/5340-30J	200 ft (60.96 m)

An ICAO/FAA comparison working paper gives the ICAO Annex 14 recommendation as uniform longitudinal intervals not exceeding 60 m, distinct from the FAA 200 ft figure — this calculator uses a standard selector rather than one shared value.

Why the standard selector matters

Achieved spacing	ICAO (60 m)	FAA (60.96 m)
60.50 m	FAIL	PASS

Advanced geometry — worked example

Runway width W = 45 m, edge-light offset D_E = 3 m:

W_light = W + 2D_E = 45 + 6 = 51.00 m (edge lights sit outside the pavement edge)

Caution-zone worked examples

Standard	Runway length	Limit	L_caution
FAA	10,000 ft	L / 2 = 5,000 ft	2,000 ft
FAA	3,000 ft	L / 2 = 1,500 ft	1,500 ft
FAA	2,000 ft	L / 2 = 1,000 ft	1,000 ft
ICAO	3,000 m	L / 3 = 1,000 m	600 m
ICAO	1,500 m	L / 3 = 500 m	500 m

What this calculator does not do

It does not select an ALS/threshold configuration, does not maintain a figure-specific ICAO endpoint database, and does not replace review against the approved aerodrome lighting layout. Coordinate generation and exact ICAO figure-level endpoint rules are treated as engineering judgement inputs (offset mode, endpoint reference), not hidden defaults.

Runway Edge Light Spacing and Quantity Calculator: Frequently Asked Questions

Quick answers on edge-light spacing, quantity, caution-zone colour and the field verification checks.

What does the Runway Edge Light Spacing and Quantity Calculator do?

It generates the edge-light station positions along the runway, checks the achieved spacing against the applicable maximum, and reports the quantity for the left and right rows. It also derives the caution-zone colour limits, checks the lateral geometry, verifies measured positions on an existing installation, and produces a station schedule and PDF report.

What is the maximum edge-light spacing under ICAO and FAA?

ICAO Annex 14 uses 60 m for an instrument runway and 100 m for a non-instrument runway. FAA AC 150/5340-30J uses 200 ft (60.96 m). The two are kept as distinct values and are not treated as equal. For example, an achieved spacing of 60.50 m fails the ICAO 60 m limit but passes the FAA 60.96 m limit.

How is the number of edge lights calculated?

For usable length L and design spacing Sdesign, the number of intervals is N = ⌈L ÷ Sdesign⌉ and the actual spacing is Sactual = L ÷ N, which must not exceed Smax. N intervals give N + 1 positions per side. The calculator builds the actual station array from chainage 0 to L rather than relying on N + 1 alone, because the final count depends on the endpoint and reference convention.

Where should edge lights be placed relative to the runway?

FAA AC 150/5340-30J places them parallel to the centreline, 0.6 to 3.0 m from the edge of full-strength pavement, uniformly spaced and symmetrical. The calculator pre-sets 3.0 m for jet runways and 0.6 m for non-jet runways as a planning default only, so confirm the offset against the AC and the approved layout, and a custom value outside 0.6 to 3.0 m is flagged. Under ICAO the lights sit on the runway edge or up to 3 m outside it. The distance between the two rows is W + 2DE, so a 45 m runway with a 3 m offset gives 51.00 m.

How is the yellow caution zone determined?

For MIRL and HIRL, yellow replaces white in the caution zone, seen facing the instrument approach threshold, and white shows in the opposite direction. The zone length is min(2000 ft, L ÷ 2) under FAA and min(600 m, L ÷ 3) under ICAO. It lies at the far end from the instrument approach threshold, and it is applied to each approach independently.

Does a displaced threshold change the edge-light count?

No. Edge-light chainage and the caution-zone reference run from Threshold or Runway-End A across the full physical runway length. Threshold displacement affects the landing-threshold reference used for threshold lighting in Calculators #02 and #05, and is entered here for documentation only.

How does the existing-installation check work?

Enter the measured chainage of the fixtures on one side. The calculator reports the achieved spacing between each pair of fixtures against Smax as PASS or FAIL, and also reports the cumulative deviation from the design stations. The cumulative figure matters because individually acceptable intervals can still hide a growing positional drift along the runway. Verify the opposite side separately if it may differ.

Is the result a final design or BOQ?

No. The calculator produces station positions, spacing and quantity from the values entered. It does not select an ALS or threshold configuration, does not maintain a figure-specific ICAO endpoint database, and does not replace the approved aerodrome lighting layout. Where a separate runway-end or threshold fitting is provided at chainage 0 or L, count it under Calculator #02 or #05 rather than as an extra edge light here.

Important Notice, Disclaimer & Limitation of Liability

Please read before relying on any content on this page or on any result or record produced by it.

Specific to this page: Applies to the Runway Edge Light Spacing & Quantity (calculator), including its PDF reports.

Calculated results. Results, tables, charts, status indicators (such as “OK”, “within limit” or “pass”/“fail”), recommended or selected values and the example presets on this page are first-pass planning and training estimates calculated in your browser from the values you enter, using simplified formulas, generic tables and typical values. They do not take account of every factor of a real installation, may contain errors or rounding differences, and are not a design, specification, selection, sizing, procurement or acceptance decision. A competent person must check them against the approved design, the manufacturer’s data and the applicable standard before any use. “Recommended” means an indicative estimate, not an endorsement of any rating, product or supplier.

Spacing, quantity and layout. Spacings, light counts, patterns, dimensions and configurations are simplified readings of ICAO Annex 14, FAA advisory circulars and similar documents and may not reflect the edition, aerodrome reference code, runway category, local variations or approved design that apply to your aerodrome. Counts and layouts are planning estimates only; the approved aerodrome lighting layout, the contract specification and the competent regulator prevail. Nothing here is an approved design or drawing, or evidence that any lighting meets a standard.

Bills of quantities and material lists. BOQ and material quantities are first-pass estimates based on your inputs and generic allowances. They omit items, wastage, spares, civil works, cable lengths and site conditions that a real project will need. A BOQ produced here is not a tender document, quotation, purchase order or an approved material take-off, and no price, product or supplier is implied. We do not sell the items listed.

Reports, downloads and printouts. PDF reports, CSV files and printed pages produced by this tool are uncontrolled working records generated in your browser. They are not approved designs, drawings, controlled documents, certificates, permits or regulatory records. Calculator numbers, revision labels, dates, project names, signature or approval fields on them are layout only and carry no authority unless made under your own approved document-control system. You must not present an output as an approved, verified or certified document. If you enter personal or confidential information, you are responsible for handling any exported file lawfully, including under the Digital Personal Data Protection Act, 2023.

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Educational reference only. This page is general information for competent, suitably trained and authorised aviation and electrical personnel and for learners. It is not professional engineering, legal, regulatory or safety advice, is not an approved procedure, and creates no professional or client relationship. Values, tolerances, intervals, sequences and examples are generic and indicative; real installations differ by design, make, model, age and condition, and your aerodrome’s approved procedures and the manufacturer’s documents prevail.

Standards and regulations. References to ICAO, FAA, IEC, IEEE, ISO, BIS (IS), DGCA, AAI and other documents are paraphrased summaries for orientation. They are not official text, may be incomplete or superseded, and do not state what any airport, project or regulator requires. Always consult the current official editions and the controlling project specification. Using this tool, or following its output, does not guarantee compliance with any law, standard or approval, and nothing on this page states that any airport, product or project complies or does not comply.

Safety. Series-circuit airfield ground lighting equipment can carry lethal voltages. Treat every circuit as live until it has been isolated, locked out, proved dead and discharged under your aerodrome’s permit-to-work and LOTO procedures and the manufacturer’s instructions. Nothing on this page authorises work on live equipment, bypassing of any safety device or interlock, installation, adjustment, energisation, return to service, a change of operating category (CAT I/II/III), a NOTAM or any certification decision; those rest with the aerodrome operator, the air navigation service provider and the competent regulator.

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Notice v2.9 · 27 October 2026 · Full terms: Legal & Disclaimer

Runway Edge Light Spacing & Quantity

Runway & Standard

Threshold & Runway-End Reference

Edge-Light Lateral Geometry

Display & Precision

Existing-Installation Field Verification (optional)

Verification results

Report details

Quantity schedule

Edge-Light Quantity Schedule

Station schedule

Build-up

How This Calculator Works

Edge-light lateral position

Symmetrical edge-light rows

Engineering quantity formula

Threshold/runway-end reference architecture

Caution-zone colour

Existing-installation compliance

ICAO vs. FAA maximum spacing

Why the standard selector matters

Advanced geometry — worked example

Caution-zone worked examples

What this calculator does not do

Runway Edge Light Spacing and Quantity Calculator: Frequently Asked Questions

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Important Notice, Disclaimer & Limitation of Liability