Area by DMD / DPD Traverse Calculator
A free, browser-based tool. Runs entirely in your browser — no sign up, nothing stored.
Latitudes & departures
One row per traverse leg (the balanced latitude and departure, in metres). Sign matters: N/E positive, S/W negative.
| Latitude (m) | Departure (m) | |
|---|---|---|
Area
| Latitude | Departure | DMD | DMD × lat |
|---|---|---|---|
| 0.000 | 100.000 | 100.000 | 0.000 |
| 100.000 | 0.000 | 200.000 | 20000.000 |
| 0.000 | -100.000 | 100.000 | 0.000 |
| -100.000 | 0.000 | 0.000 | 0.000 |
DMD₁ = departure₁; DMDᵢ = DMDᵢ₋₁ + departureᵢ₋₁ + departureᵢ. Area = |Σ(DMD × latitude)| ÷ 2.
How to use this calculator
- Enter each leg's balanced latitude and departure (metres), in order around the traverse.
- Keep the signs right: northing/easting positive, southing/westing negative.
- Read the enclosed area, plus the DMD column so you can see the working.
How it works
The Double Meridian Distance of the first leg is its departure; each later DMD = the previous DMD + the previous departure + this leg's departure.
Twice the area is Σ(DMD × latitude); the enclosed area is the absolute value of that, halved. It's the traditional hand method that matches the area-by-coordinates result.
Worked example
A 100 m × 100 m square. Legs (lat 0, dep +100), (+100, 0), (0, −100), (−100, 0) give Σ(DMD × lat) = 20,000, so the area is 10,000 m² (1 ha).
Frequently asked questions
What's the difference from area by coordinates?
Same answer, different inputs. DMD works from the legs' latitudes and departures (a closed traverse); area-by-coordinates works from the corner eastings and northings.
Is this official course material?
No. It is free study support mapped to surveying course levels — not official North Metropolitan TAFE content or advice. Always follow your lecturer and the official assessment brief, and check your own working.
Related tools
Tip: Enter any known values to calculate the remaining results.
All calculations run in your browser. Your inputs are never saved or transmitted.