Area By Double Meridian Distance Calculator

Work out area by double meridian distance instantly with clear inputs, formula shown and shareable results.

About Area By Double Meridian Distance Calculator

The double meridian distance method computes traverse area directly from latitudes and departures without needing coordinates. Each leg's DMD is the previous DMD plus the previous and current departures, and multiplying by the latitude and summing gives twice the area. The closure error of the legs is reported because a poorly closing traverse gives an unreliable area.

Formulas

Double meridian distance

DMD of a leg = DMD of the previous leg + departure of the previous leg + departure of this leg

Area

Area = 0.5 x |sum of (DMD x latitude)|

Worked example

With the default values below, Area By Double Meridian Distance Calculator returns Enclosed area of 1,150.0000. Change any input above and every figure here is recalculated in your browser.

Inputs used

Traverse legs as latitude,departure pairs: 30,40; -20,50; -10,-90
Scale factor applied to the valuesminimum 0: 1

Results

Enclosed area: 1,150.0000 m²
Double area from the DMD sum: 2,300.0000 m²
Legs used: 3
Closure error of the legs: 0.0000 m

Step by step

1Values used
2Double meridian distance
3Area
4Enclosed area= 1,150.0000 m²
5Double area from the DMD sum= 2,300.0000 m²
6Legs used= 3
7Closure error of the legs= 0.0000 m

Assumptions and limits

The result is derived only from the 2 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 4 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

How is the Area By Double Meridian Distance figure worked out?

DMD of a leg = DMD of the previous leg + departure of the previous leg + departure of this leg. The double meridian distance method computes traverse area directly from latitudes and departures without needing coordinates.

Why use DMD rather than coordinates?

It was the standard hand method because it works straight from the bearing and distance reductions with no coordinate computation. It remains a useful independent check on a coordinate-based area.

What values do I need to enter?

This calculator takes 2 inputs: Traverse legs as latitude,departure pairs, Scale factor applied to the values. The pre-filled defaults are a realistic worked example — replace them with your own site or project figures.