How much soil does a 4 by 8 raised bed need?

A 4 by 8 foot rectangular space filled 10 inches deep holds exactly 80/3 cubic feet: 26.67 cubic feet and 0.99 cubic yards when rounded, or about 755 litres. It needs 18 bags of 1.5 cubic feet, 27 bags of 1 cubic foot or 14 bags of 2 cubic feet. At 12 inches it holds 32 cubic feet and needs 22 bags of 1.5; at 6 inches it holds 16 cubic feet and needs 11. Supply your own fill depth and bag capacity.

How deep does a raised bed need to be?

The calculator does not choose a horticulturally suitable depth. Its 10 inch starting depth is an editable arithmetic example. A 4 by 8 foot space holds 16 cubic feet at 6 inches, 80/3 cubic feet at 10 inches and 48 cubic feet at 18 inches. Choose the fill depth from your own bed and growing requirements, then enter it.

How many bags of soil are in a cubic yard?

One cubic yard is exactly 27 cubic feet. For that supplied volume the whole-bag ceilings are 27 bags of 1 cubic foot, 18 of 1.5, 14 of 2, or 9 of 3. With capacities supplied as 40 or 50 litres, the ceilings are 20 or 16 bags respectively. The calculator works from measured dimensions or a known area and depth; it has no direct supplied-volume input. Bag capacity units can be cubic feet, litres or cubic metres.

Is topsoil different from potting mix for this calculator?

The volume calculation does not identify the material. The same rectangular dimensions give the same capacity for topsoil, compost or potting mix, with the bag count based on the capacity you supply. It does not calculate a mix recipe, density, suitability, settling or product-specific quantity. Use the capacity printed on your bag.

How do I work out the soil for a pot or a planter?

Pot mode measures identical straight-sided cylinders from an inside diameter, fill height and a positive whole count. For a 12 inch inside diameter and 10 inch fill height, one cylinder holds 5π/24 cubic feet, approximately 0.65 cubic feet or 19 litres. Three hold 5π/8 cubic feet and need 2 bags of 1.5 cubic feet. The diameter and height are in the selected inches or centimetres. A tapered container, drainage material and a root ball require additional geometry or displacement information that this workflow does not accept.

How much soil do I need to fill a hole?

Fill mode accepts a rectangular space or a known area and your chosen depth. A 3 by 3 foot space with a 24 inch fill depth holds 18 cubic feet and needs 12 bags of 1.5 cubic feet. A 20 by 3 foot trench with a 4 inch layer holds 20 cubic feet and needs 14 bags. For separate spaces, add the full volumes before rounding the combined bag requirement; adding already rounded bag counts can overcount. There is no multiple-space total or price comparison here.

Does it work in metres and litres?

Yes. Select Metres for plan measurements, Centimetres for the fill depth or cylinder diameter and height, and L for bag capacity. A 1.2 by 2.4 metre space with a 25 centimetre layer holds exactly 720 litres, or 0.72 cubic metres. These unit choices are independent. Conversions preserve the entered physical measurement as an exact decimal or fraction, so one metre becomes 1250/381 feet. Cylindrical quantities are marked approximate.

Is anything uploaded, and does it cost anything?

Calculation runs locally and needs no account. Valid deliberate changes can be saved in this browser; defaults and restored settings do not rewrite storage. Invalid drafts and unusable saved records are preserved, and Forget saved settings removes the record explicitly. The raised-bed, fill and pot pages present their own modes without saving those presets; raised-bed presents a 10 inch depth converted into the selected depth unit.

Soil Calculator

Work out how much soil you need for a raised bed, a hole or trench, or a round pot, from the measurements you actually took. Choose a rectangular space or known area with a fill depth, or identical straight-sided cylindrical containers with an inside diameter, fill height and whole count. See cubic feet, cubic yards, litres, cubic metres and a whole-bag ceiling from the capacity you supply. Plan, depth and bag units are independent and convert exactly; cylinder quantities use a bounded approximation of pi. Complete selectable working is available. Valid deliberate changes can be saved locally, and nothing is uploaded.

Soil needed4 ft by 8 ft at 10 in

Cubic feet26.67

0.99 cu yd · 755.12 litres · 0.76 m³18 bags at 1.5 ft³, rounded up

2.97 m² combined plan area × 10 in = 0.76 m³; bag division uses the full combined volume.

Supply your measured space, chosen fill depth and the capacity printed on your bag. Pot mode measures identical straight-sided cylinders using an inside diameter and fill height; it does not model taper or a plant. The initial dimensions and 1.5 ft³ bag are editable examples. Plan, depth and bag units are independent. Unit changes preserve measurements as exact decimals or fractions. Results round to two decimal places; ≈ marks a cylinder approximation and … marks an abbreviation. Complete values are below.

Complete selectable calculation

Soil Calculator - supplied quantity estimate
Mode: bed; 4 ft by 8 ft at 10 in
Supplied bag capacity: 1.5 ft³
Combined plan area: exact 2.97289728 m² (1161288/390625)
cubicMetres: exact 0.75511590912 m³ (36870894/48828125)
cubicFeet: exact 80/3 ft³ (80/3)
cubicYards: exact 80/81 yd³ (80/81)
Litres: exact 755.11590912 L (294967152/390625)
Whole bags: 18
A supplied rectangular space or known area and chosen fill depth, or identical straight-sided cylindrical containers with an inside diameter, fill height and exact positive whole count. Defaults are editable examples, not suitable depths or product recommendations.
Rectangle and known-area arithmetic and unit conversions are exact. Cylinders are π times the stated coefficient; decimal displays use a 100-place bound for π and are approximate. A bag range means that bound straddles a whole-bag boundary.
Bag counts round up from the full combined volume before display rounding. Large previews are abbreviated; this report retains complete values. Litres are exactly 1000 times cubic metres.
No taper, root-ball displacement, drainage, settling, compaction, weight, soil mix, material suitability, supplier, delivery or price is inferred. Separately rounded bag counts do not establish the ceiling for a combined job.

A 4 by 8 raised bed10 in of mix
26.67 cu ft · 18 bags at 1.5 ft³
A hole to fill3 ft by 3 ft, 2 ft deep
18.00 cu ft · 12 bags at 1.5 ft³
A 12 in round pot10 in of mix
≈ 0.65 cu ft · 1 bags at 1.5 ft³

Supplied quantities and complete working. Exact arithmetic for length by width by depth or known area by depth, with quantities converted without rounding until the last step. The cylinder formula for a pot uses a bounded approximation of pi; a bag-count range marks an uncertain boundary. It cannot know how far soil settles after its first watering, how much room root balls take, or what a brand actually puts in a bag. Open the complete calculation for exact quantities, cylinder bounds and the assumptions used.

Common questions

How much soil does a 4 by 8 raised bed need?: A 4 by 8 foot rectangular space filled 10 inches deep holds exactly 80/3 cubic feet: 26.67 cubic feet and 0.99 cubic yards when rounded, or about 755 litres. It needs 18 bags of 1.5 cubic feet, 27 bags of 1 cubic foot or 14 bags of 2 cubic feet. At 12 inches it holds 32 cubic feet and needs 22 bags of 1.5; at 6 inches it holds 16 cubic feet and needs 11. Supply your own fill depth and bag capacity.
How deep does a raised bed need to be?: The calculator does not choose a horticulturally suitable depth. Its 10 inch starting depth is an editable arithmetic example. A 4 by 8 foot space holds 16 cubic feet at 6 inches, 80/3 cubic feet at 10 inches and 48 cubic feet at 18 inches. Choose the fill depth from your own bed and growing requirements, then enter it.
How many bags of soil are in a cubic yard?: One cubic yard is exactly 27 cubic feet. For that supplied volume the whole-bag ceilings are 27 bags of 1 cubic foot, 18 of 1.5, 14 of 2, or 9 of 3. With capacities supplied as 40 or 50 litres, the ceilings are 20 or 16 bags respectively. The calculator works from measured dimensions or a known area and depth; it has no direct supplied-volume input. Bag capacity units can be cubic feet, litres or cubic metres.
Is topsoil different from potting mix for this calculator?: The volume calculation does not identify the material. The same rectangular dimensions give the same capacity for topsoil, compost or potting mix, with the bag count based on the capacity you supply. It does not calculate a mix recipe, density, suitability, settling or product-specific quantity. Use the capacity printed on your bag.
How do I work out the soil for a pot or a planter?: Pot mode measures identical straight-sided cylinders from an inside diameter, fill height and a positive whole count. For a 12 inch inside diameter and 10 inch fill height, one cylinder holds 5π/24 cubic feet, approximately 0.65 cubic feet or 19 litres. Three hold 5π/8 cubic feet and need 2 bags of 1.5 cubic feet. The diameter and height are in the selected inches or centimetres. A tapered container, drainage material and a root ball require additional geometry or displacement information that this workflow does not accept.
How much soil do I need to fill a hole?: Fill mode accepts a rectangular space or a known area and your chosen depth. A 3 by 3 foot space with a 24 inch fill depth holds 18 cubic feet and needs 12 bags of 1.5 cubic feet. A 20 by 3 foot trench with a 4 inch layer holds 20 cubic feet and needs 14 bags. For separate spaces, add the full volumes before rounding the combined bag requirement; adding already rounded bag counts can overcount. There is no multiple-space total or price comparison here.
Does it work in metres and litres?: Yes. Select Metres for plan measurements, Centimetres for the fill depth or cylinder diameter and height, and L for bag capacity. A 1.2 by 2.4 metre space with a 25 centimetre layer holds exactly 720 litres, or 0.72 cubic metres. These unit choices are independent. Conversions preserve the entered physical measurement as an exact decimal or fraction, so one metre becomes 1250/381 feet. Cylindrical quantities are marked approximate.
Is anything uploaded, and does it cost anything?: Calculation runs locally and needs no account. Valid deliberate changes can be saved in this browser; defaults and restored settings do not rewrite storage. Invalid drafts and unusable saved records are preserved, and Forget saved settings removes the record explicitly. The raised-bed, fill and pot pages present their own modes without saving those presets; raised-bed presents a 10 inch depth converted into the selected depth unit.

Exact arithmetic for length by width by depth or known area by depth, with quantities converted without rounding until the last step. The cylinder formula for a pot uses a bounded approximation of pi; a bag-count range marks an uncertain boundary. It cannot know how far soil settles after its first watering, how much room root balls take, or what a brand actually puts in a bag.