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Drone Flight Line Spacing Calculator

Maximum distance between flight lines for your side overlap — with line counts, offsets and clipped segments over a rectangle or polygon.

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How to use this calculator

Inputs

Maximum distance between flight lines for your side overlap — with line counts and offsets over a rectangle or polygon.

Footprint
Overlap
%

0 is valid; exactly 100 % is not (the aircraft would never advance).

Layout

Enter the values and press Calculate.

Or load an example to see a worked result.

Flight strips and side overlap (plan)
Schematic
Flight strips and side overlap (plan)Schematic of parallel flight strips over a survey area.q = F_c × (1 − side overlap)
Adjacent strips are one across-track footprint wide; their centres are q apart, so the darker band where they overlap is F_c − q wide.
Calculate first: a stale result cannot be exported.

Batch from CSV

One row per calculation, with a header row. Values use the units currently selected in the form above. Up to 10,000 rows; nothing is uploaded.

Before you rely on this: First-pass guide only. Verify safety-critical or regulated work against the relevant standards, your project requirements and a qualified professional.

How to use this calculator

  1. Work from the across-track footprint, or from the camera, height and image orientation.
  2. Enter the side overlap (0 is valid, 100 % is not) — or use the inverse mode to turn a spacing into an overlap.
  3. Optionally lay the lines over a rectangle (site width) or a polygon of E, N vertices with a heading.
  4. Read the maximum spacing, the line count, the evenly spread actual spacing and the line-offset table.

How it works

q = F_c × (1 − side overlap). Lines over a width C: max(1, ⌈max(0, C − F_c) ÷ q⌉ + 1), centres spread evenly from F_c/2 to C − F_c/2, so the actual spacing is at or below the requested maximum.

One line has no neighbour, so its adjacent overlap is 'not applicable'. In the inverse mode a spacing wider than the footprint is shown as a gap, not a negative overlap.

Polygon mode rotates to your heading, clips each strip to the polygon (whole-strip edge policy by default) and lists every segment. With a constant flight elevation over rising ground the footprint shrinks and the overlap there falls below target.

Worked example

F_c 200 m, 65 % side overlap, 340 m site. q = 200 × (1 − 0.65) = 70 m. Lines = ⌈(340 − 200) ÷ 70⌉ + 1 = 3, at 100, 170 and 240 m from the edge, actual spacing 70 m. A 100 m-wide site needs one centred line, with no adjacent overlap.

Frequently asked questions

Why is the actual spacing smaller than the maximum?

Lines are spread evenly so the last strip reaches the far edge, which usually tightens the spacing and raises the real overlap.

Is this a flight plan I can upload?

No. It is planning geometry; it does not check airspace, obstacles or terrain following and is not an aircraft mission file.

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Cite this tool

Zerdly. (2026). Drone Flight Line Spacing Calculator. Retrieved from https://www.zerdly.com/tools/drone-flight-line-spacing-calculator/

Tip: Enter any known values to calculate the remaining results.

Designed to run locally in your browser. Tool inputs are not intentionally stored by Zerdly unless stated otherwise.