Gardening & Landscaping · Free calculator

Garden Bed Calculator

Estimate soil fill volume and bags for one or more identical rectangular raised garden beds using internal measurements.

Your measurements

Prefilled values are editable examples. Measure your own space and check the selected units. Allowance and bed count may be left blank; all other fields are required.

Length / width unit

Depth unit

Bag volume unit

Internal bed length (m)

Enter your measured dimension in the selected unit. Zero gives zero area or volume.

Internal bed width (m)

Enter your measured dimension in the selected unit. Zero gives zero area or volume.

Soil fill / layer depth (cm)

Uniform material depth, not a dimension in square or cubic units.

Number of identical beds

Optional: leave blank for 1 bed. Enter a whole number; 0 is allowed.

Volume per bag (liters)

Use the volume printed on the bag, not its weight. Must be greater than zero.

Changing units converts the current measurements; changing any input clears the previous result.

Your estimate

Material quantities

Review the example measurements, select your units and calculate. No quantities have been calculated yet.

How much soil do I need for a raised garden bed?

Volume per bed = internal length × internal width × soil fill depth. Total volume = volume per bed × number of identical beds. Round total volume ÷ bag volume upward for the combined bag count.

Worked example

One bed measuring 2 m × 1 m inside, filled 30 cm deep, needs 0.6 m³. At 50 liters per bag, that is 12 bags. Two identical beds need 1.2 m³ and 24 bags.

Unit conversions

1 ft = 0.3048 m; 1 in = 0.0254 m; 1 cm = 0.01 m. 1 yd³ = 27 ft³ = 0.764554857984 m³; 1 liter = 0.001 m³. 1 acre = 4,046.8564224 m². 1 lb = 0.45359237 kg.

Assumptions & limitations

Enter internal dimensions and intended soil fill depth, not outside frame size or full wall height. Bed count defaults to 1; enter 0 for a zero-volume plan.
Assumes identical rectangular beds with vertical sides. Settling, existing soil, logs, drainage layers and other materials change the actual fill needed. Deduct their occupied depth or volume from your measurements.
No settlement allowance is automatically added. For extra material, adjust fill depth or use the Soil Calculator with an explicit allowance.