Runway Light Quantity

Nominal fixture-quantity tool for a full runway lighting configuration — edge, threshold, wing-bar and runway-end lights, calculated as separate components rather than one merged total.

About this calculator

Runway edge-light quantity reuses Calculator #01's validated spacing engine. Threshold-light quantity is split by operational category — a fixed minimum for non-instrument/non-precision runways, and a geometry-based calculation from the edge-light-row span for CAT I/II/III. Runway-end lights are shared with threshold fittings where the threshold sits at the runway extremity, and treated as a separate component where the threshold is displaced. Wing-bar and displaced-threshold runway-end quantities are entered against the approved layout rather than derived from a generic formula, since ICAO's figure-level endpoint arrangement is not reproduced here.

Quick start

Runway & Standard

Design Standard

Rule note

Governs edge-light maximum spacing and the threshold-light minimum-quantity rule. DGCA/AAI projects generally follow the ICAO table unless the approved project specification says otherwise.

Edge-Light Maximum Spacing (Project)

Rule note

Enter the approved project criterion, in the input units below. Do not assume this equals ICAO or FAA values.

Operational Classification

Rule note

Drives both the edge-light spacing table and the threshold-light rule: fixed minimum for non-instrument/non-precision, 3 m-spacing geometry for CAT I/II/III.

Runway / Design Length

Rule note

Threshold-to-threshold, or the applicable calculation segment. For a displaced threshold this is the full physical runway length — see the displacement field below.

Runway Width

Rule note

Used only for CAT I/II/III threshold-light geometry below — not required for non-instrument/non-precision runways (fixed minimum applies).

Edge-Light-Row Geometry (for threshold-light span)

Edge-Light Row Spacing

Rule note

The distance between the two runway edge-light rows may differ from the pavement width. Use the actual project drawing value where available.

Edge-Light Lateral Offset (outside the pavement edge, each side)

Rule note

W_E = Runway width + 2 × offset. ICAO allows edge lights on the runway edge or outside it by not more than 3 m. Leave at 0 if they sit on the edge.

Edge-Light-Row Span (W_E) — User-Defined

Rule note

Enter the actual distance between the two edge-light rows from the approved layout.

Threshold-Light Maximum Spacing

Rule note

ICAO CAT I/II/III threshold-light criterion — uniform spacing not exceeding this value between the edge-light rows. Default 3 m; edit only if a different standard applies.

Endpoint Arrangement

Rule note

The exact CAT I/II/III fixture count depends on the figure-level endpoint convention (outermost position, centreline treatment), which this calculator does not assume by default — confirm against the applicable standard figure before using as a final quantity.

Custom Endpoint Adjustment

Rule note

Added to the interval count ⌈W_E / S_max⌉ to obtain the threshold-fixture count.

Threshold, Wing Bar & Runway-End Configuration

Threshold displaced from runway extremity

Runway Ends Counted

Rule note

Each end is a threshold for one direction and the runway end for the other. Threshold, wing-bar and runway-end quantities are worked out for one end and multiplied by this count. If the two ends differ (for example only one threshold is displaced), count them separately.

Threshold Displacement

Rule note

Distance from the physical runway extremity to the displaced threshold, in the input units above.

Wing-Bar Configuration

Rule note

Relevant mainly to non-instrument/non-precision runways with a displaced threshold — wing bars can remove the threshold-light requirement in that configuration.

Wing-Bar Fixture Quantity

Rule note

Quantity for one threshold, multiplied by the ends counted. Enter per the approved project layout — a generic wing-bar formula is not applied here, since the arrangement is figure-specific. ICAO needs at least five lights in each wing bar, extending at least 10 m outward from the edge-light line with the innermost light on that line, so at least 10 per threshold. If that inner light is also an end fixture of the threshold row, count it only once.

Runway-End Fixture Quantity (displaced-threshold case, per end)

Rule note

With a displaced threshold, runway-end lighting at the physical extremity is a separate geometric element from the threshold — enter per the approved layout rather than assuming it equals the threshold count.

Display, Validation & Field Checks

Display & Validation Settings

Rule note

Output units, decimal precision, and configurable min/max plausible length (in metres) — flags likely data-entry errors only, never blocks calculation.

Existing Edge-Light Positions Per Side (optional — field check)

Verifies achieved edge-light spacing against the applicable maximum.

Existing Threshold-Light Quantity (optional — field check)

Rule note

Compares an installed count at one threshold against the calculated nominal threshold quantity for one end.

Runway intersection present

Report details

Project Name (for report)

Runway Designation (for report)

Quantity schedule

Runway Light Quantity Schedule

Component	Calculation Basis	Quantity
Edge lights — left	Longitudinal spacing	—
Edge lights — right	Longitudinal spacing	—
Edge lights — total	2(N + 1)	—
Threshold lights	Runway category / configuration	—
Threshold wing-bar lights	Applicable configuration	—
Runway-end lights	Runway-end configuration	—
Calculated nominal total		—

Calculated / Nominal Quantity — not a Final BOQ Quantity. Threshold/runway-end sharing is applied only where the threshold sits at the runway extremity under the selected standard.

Build-up

Edge-Light Max Spacing

—

Edge Intervals (N)

—

Edge Positions / Side

—

Edge-Light-Row Span (W_E)

—

Threshold Interval Count (N_T)

—

Threshold Achieved Spacing

—

Calculator #02 | Rev. 1.2 | 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

Runway lighting quantity is broken into separate components rather than one merged total — ICAO treats runway edge lights, threshold/wing-bar lights, and runway-end lights as distinct provisions with different spacing rules.

Edge-light quantity (inherited from Calculator #01)

For design length L against maximum interval S_max, rounding up (never ordinary rounding, since any excess is a non-compliance):

N = ⌈ L / S_max ⌉ → P_side = N + 1 → P_total = 2(N + 1)

This calculator reuses the same spacing engine as Calculator #01 so the two tools cannot silently disagree on the edge-light count for the same runway.

Non-instrument / non-precision threshold

ICAO 5.3.10 sets a fixed minimum of 6 threshold lights where threshold lights are required. Where the threshold is displaced and wing-bar lights are provided, the displaced-threshold + wing-bar configuration can remove the threshold-light requirement entirely — this calculator applies that exception only when both conditions are selected, and never infers it from one alone.

Precision CAT I / II / III threshold geometry

The threshold-light count is tied to the edge-light-row span W_E and the maximum spacing criterion (3 m by default):

N_T = ⌈ W_E / S_max,T ⌉ → Q_T = N_T + endpoint adjustment

The endpoint adjustment is deliberately not hard-coded. Whether the final fixture count is N_T, N_T + 1, or another figure-specific value depends on whether both edge-light-row endpoints carry a fixture, whether a centreline position exists, and the exact arrangement in the applicable standard figure (see the applicable ICAO Annex 14 figure). This calculator defaults to +1 but exposes the setting so it is never a hidden assumption.

Runway-end lights — shared or separate

ICAO 5.3.11 requires runway-end lights for a runway equipped with edge lights, but permits fittings serving as threshold lights to also serve as runway-end lights when the threshold is at the runway extremity. This calculator applies that sharing logic automatically when the threshold is not displaced (no additional fixtures added), and treats runway-end lighting as a separate, user-entered component whenever a threshold displacement is selected — since a displaced threshold makes threshold lighting and runway-end lighting distinct geometric elements.

Wing bars are not "extra edge lights"

A wing bar is a separate threshold-lighting arrangement, not simply additional runway edge lights, and its exact fixture count is figure-specific. This calculator asks for the wing-bar quantity directly against the approved layout rather than generating one from a generic formula.

Threshold-light rule by category

Runway operation	Threshold-light requirement
Non-instrument	Min. 6 (where required)
Non-precision	Min. 6 (where required)
Precision CAT I	At least the 3 m-spacing count (two-group layout permitted)
Precision CAT II	≤ 3 m uniform spacing
Precision CAT III	≤ 3 m uniform spacing

Working basis: ICAO Annex 14, Volume I. Independently confirm against the exact edition/amendment applicable to your project before relying on this as a standards reference.

Worked geometry examples (CAT II/III, 3 m criterion)

W_E	N_T	Achieved spacing
30 m	10	3.00 m
44 m	15	2.93 m
46 m	16	2.88 m
45.01 m	16	2.81 m

Interval count only — apply the endpoint-adjustment setting above to convert to a final fixture count.

Quantity vs. serviceability

This calculator produces an installed fixture quantity. It does not multiply that quantity by a serviceability percentage (the percentages in the maintenance provisions of the governing standard) — quantity and serviceability are separate calculations and should not be combined here.

Indian / AAI & DGCA projects

Treat the design-basis hierarchy as: project specification / approved drawing → applicable DGCA requirement → ICAO Annex 14 where adopted → FAA only where the project specification explicitly calls for it. Select DGCA / Indian or Project-Specific above rather than assuming an ICAO or FAA default applies.

Runway Light Quantity Calculator: Frequently Asked Questions

Quick answers on how the calculator counts edge, threshold, wing-bar and runway-end lights.

What does the Runway Light Quantity Calculator do?

It works out a calculated nominal fixture quantity for a runway, split into edge lights, threshold lights, threshold wing-bar lights and runway-end lights. These are kept as separate components because ICAO treats them as distinct provisions with different spacing rules.

How are runway edge lights counted?

The number of intervals is N = ⌈L ÷ Smax⌉, rounded up because any excess spacing is a non-compliance. That gives N + 1 positions per side and 2(N + 1) edge lights in total. The maximum spacing follows the design standard and runway classification you select. The same spacing engine is used as in Calculator #01, so the two tools cannot disagree on the edge-light count.

How many threshold lights does a non-instrument or non-precision runway need?

ICAO 5.3.10 sets a fixed minimum of 6 threshold lights where threshold lights are required. If the threshold is displaced and wing-bar lights are provided, that configuration can remove the threshold-light requirement. The calculator applies this exception only when both conditions are selected, and never infers it from one alone.

How are CAT I, II and III threshold lights calculated?

The threshold-light count is tied to the edge-light-row span WE, which is the runway width plus twice the edge-light offset. The interval count is NT = ⌈WE ÷ Smax,T⌉, with a default maximum spacing of 3 m, and the fixture count is NT plus an endpoint adjustment. For example, WE = 30 m gives 10 intervals at 3.00 m.

Why is the endpoint arrangement a setting I have to choose?

Whether the final fixture count is NT, NT + 1 or another figure-specific value depends on whether both edge-light-row endpoints carry a fixture and on the exact arrangement in the applicable standard figure. The calculator defaults to +1 but exposes the setting so it is never a hidden assumption. Confirm it against the applicable ICAO Annex 14 figure.

Are runway-end lights counted separately from threshold lights?

It depends on the threshold. ICAO 5.3.11 permits fittings that serve as threshold lights to also serve as runway-end lights when the threshold is at the runway extremity, so no additional fixtures are added in that case. With a displaced threshold, the runway-end lights become a separate element and their quantity is entered per the approved layout.

Which design standard should I select for an Indian project?

The design-basis order is the project specification or approved drawing, then the applicable DGCA requirement, then ICAO Annex 14 where adopted, and FAA only where the project specification calls for it. Select DGCA / Indian or Project-Specific rather than assuming an ICAO or FAA default applies. DGCA and AAI projects generally follow the ICAO table unless the approved project specification says otherwise.

Can I use the result as the final bill of quantities?

No. The result is a calculated nominal quantity, not a final BOQ quantity. It is an installed fixture count and does not include a serviceability percentage. CAT I, II and III threshold counts depend on the endpoint arrangement in the standard figure, and displaced-threshold wing-bar and runway-end quantities are entered against the project layout. Verify all figures against the approved aerodrome lighting drawing before issue.

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 Light 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 Light Quantity

Runway & Standard

Edge-Light-Row Geometry (for threshold-light span)

Threshold, Wing Bar & Runway-End Configuration

Display, Validation & Field Checks

Report details

Quantity schedule

Runway Light Quantity Schedule

Build-up

How This Calculator Works

Edge-light quantity (inherited from Calculator #01)

Non-instrument / non-precision threshold

Precision CAT I / II / III threshold geometry

Runway-end lights — shared or separate

Wing bars are not "extra edge lights"

Threshold-light rule by category

Worked geometry examples (CAT II/III, 3 m criterion)

Quantity vs. serviceability

Indian / AAI & DGCA projects

Runway Light Quantity Calculator: Frequently Asked Questions

Related Knowledge Hub Resources

Calculator #01

AGL Toolkit

Standards Companion

SOP Library

Talk to Precision AGL Academy

Follow the Academy

Important Notice, Disclaimer & Limitation of Liability