Calculate excavation hours and scheduled workdays from volume, production rate and efficiency, or bucket capacity and cycle time, with metric and US units and an optional additional time contingency.

Source defaults: job efficiency 80% and scheduled workday 8 hours.

Planning estimate. Keep bucket, volume and rate on the same bank, loose or compacted basis. Efficiency accounts for delays; do not count the same delay again in the contingency.

Use 100% if the entered rate already includes job delays.

Optional settings

Optional. Blank adds 0%. Use only for delays outside the efficiency allowance.

Excavation Time Formula

The following formula is used to calculate the excavation time.

ET = (V / (M × E)) × (1 + U)

Variables:

  • ET is the excavation time (hours)
  • V is the volume of material to be excavated (cubic meters)
  • M is the capacity of the machinery used (cubic meters per hour)
  • E is the efficiency of the machinery (decimal, where 1 is 100% efficiency)
  • U is the unforeseen circumstances factor (decimal, where 0.1 represents a 10% increase in time due to unexpected obstacles or weather conditions)

To calculate the excavation time, divide the volume of material to be excavated by the product of the machinery’s capacity and its efficiency. Multiply the result by the sum of 1 and the unforeseen circumstances factor. This will give the total time required for excavation, taking into account the machinery used, its efficiency, and any potential delays due to unexpected obstacles or weather conditions.

What is an Excavation Time?

Excavation time refers to the duration or period required to dig out or remove earth, rock, or other materials from a site during construction or archaeological projects. This time can vary greatly depending on the size of the project, the type of soil or rock, the machinery used, and other factors such as weather conditions or unexpected obstacles. Accurate estimation of excavation time is crucial for project planning and management.

How to Calculate Excavation Time?

The following steps outline how to calculate the Excavation Time:

  1. First, determine the volume of material to be excavated (V) in cubic meters.
  2. Next, determine the capacity of the machinery used (M) in cubic meters per hour.
  3. Next, determine job efficiency. Enter a percentage in the calculator; use its decimal fraction E in the formula. If the rate already includes delays, enter 100%.
  4. Optionally enter an additional time contingency. The calculator accepts a percentage; U in the formula is its decimal fraction. Blank adds 0%. Do not count delays already included in the rate or efficiency again.
  5. Next, use the formula ET = (V / (M * E)) * (1 + U) to calculate the Excavation Time.
  6. Finally, insert the values of V, M, E, and U into the formula and calculate the Excavation Time.

Example Problem:

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

Volume of material to be excavated (V) = 500 cubic meters

Capacity of the machinery used (M) = 50 cubic meters per hour

Efficiency of the machinery (E) = 0.8

Additional time contingency = 10% (U = 0.1). The example gives 13.75 hours, or 1.71875 scheduled workdays at 8 hours per day.