Enter the Standard Datum and the product of Distance and Slope into the calculator to determine the Benchmark Elevation. This calculator can also evaluate any of the variables given the others are known.

Benchmark Elevation Formula

The following formula is used to calculate the Benchmark Elevation. 

BE = SD + (D * S)

Variables:

  • BE is the Benchmark Elevation (meters)
  • SD is the Standard Datum, usually mean sea level (meters)
  • D is the Distance from the benchmark to the point of measurement (meters)
  • S is the Slope, or change in elevation per unit distance (meters/meter)

To calculate the Benchmark Elevation, multiply the Distance from the benchmark to the point of measurement by the Slope. Add the result to the Standard Datum. This will give the elevation of the benchmark relative to the standard datum.

What is Benchmark Elevation?

A Benchmark Elevation, often simply referred to as a benchmark, is a point of known elevation that is used as a reference in topographic surveys and mapping. It is typically marked by a small brass, aluminum, or bronze plate, which is securely fixed to a stable, immovable object such as a rock or concrete post. The exact elevation of the benchmark, relative to a standard datum (usually mean sea level), is accurately determined through precise surveying methods. Benchmarks provide a starting or reference point for surveyors to measure other elevations in the surrounding area.

How to Calculate Benchmark Elevation?

The following steps outline how to calculate the Benchmark Elevation:

  1. First, determine the Standard Datum (SD) in meters.
  2. Next, determine the Distance (D) from the benchmark to the point of measurement in meters.
  3. Next, determine the Slope (S) in meters/meter.
  4. Next, use the formula BE = SD + (D * S) to calculate the Benchmark Elevation.
  5. Finally, insert the values of SD, D, and S into the formula and calculate the result.

Example Problem:

Use the following variables as an example problem to test your knowledge:

Standard Datum (SD) = 10 meters

Distance (D) = 5 meters

Slope (S) = 2 meters/meter