Raised Bed Soil Calculator
Soil mix volume and blend ratios for raised garden beds.
Enter your values
Enter the bed length in ft.
Enter the bed width in ft.
Enter the fill depth in in.
Enter the number of beds you are working with.
Enter the bag size in cu ft.
Results update instantly as you type — no submit needed. Your values are remembered on this device, and the shareable link reopens the calculator with exactly these numbers.
- Total soil
- 53.33 cubic feet (1.98 yd3)
- Bags needed
- 36
- Topsoil (60%)
- 32 ft3
- Compost (30%)
- 16 ft3
- Aeration - perlite or bark (10%)
- 5.33 ft3
Working
- 18 x 4 x 0.83 x 2 = 53.33 ft3
Quick answer
Fill volume = length x width x fill depth x number of beds, then split it into roughly 60% topsoil, 30% compost and 10% aeration.
volume = L x W x depth x beds
At a glance
| What it does | Soil mix volume and blend ratios for raised garden beds. |
|---|---|
| Category | Home & DIY |
| Inputs needed | Bed length, Bed width, Fill depth, Number of beds, Bag size |
| Main output | Total soil |
| Formula | volume = L x W x depth x beds |
| Cost | Free — no sign-up, no download |
How to use the Raised Bed Soil Calculator
- 1Measure the inside dimensions of the bed, not the outer frame.
- 2Fill to about 2 inches below the rim so water does not wash soil over the edge.
- 3Use the 60/30/10 blend for a mix that holds moisture without going soggy.
Inputs explained
- Bed length(ft)
- Enter the bed length in ft.
- Bed width(ft)
- Enter the bed width in ft.
- Fill depth(in)
- Enter the fill depth in in.
- Number of beds
- Enter the number of beds you are working with.
- Bag size(cu ft)
- Enter the bag size in cu ft.
Worked example
Using the values the calculator loads with:
Inputs
- Bed length8 ft
- Bed width4 ft
- Fill depth10 in
- Number of beds2
- Bag size1.5 cu ft
Results
- Total soil53.33 cubic feet (1.98 yd3)
- Bags needed36
- Topsoil (60%)32 ft3
- Compost (30%)16 ft3
- Aeration - perlite or bark (10%)5.33 ft3
- 8 x 4 x 0.83 x 2 = 53.33 ft3
Frequently asked questions
Can I fill the bottom with logs or branches?
Yes - hugelkultur or a layer of coarse material can fill the lower third of a deep bed and cuts soil cost, though the bed will settle as it breaks down.
How deep should a raised bed be?
6 inches works for salads and herbs; 10 to 12 inches suits most vegetables; go 18 inches for carrots and potatoes.
What do I need to enter into the Raised Bed Soil Calculator?
Just 5 values: bed length, bed width, fill depth, number of beds, bag size. Every field starts with a realistic example, so you can change one number at a time and watch the result update instantly.
How does the Raised Bed Soil Calculator work out the answer?
Fill volume = length x width x fill depth x number of beds, then split it into roughly 60% topsoil, 30% compost and 10% aeration. It applies the formula volume = L x W x depth x beds and shows the working so you can check each step by hand.
Is the Raised Bed Soil Calculator free, and do I need an account?
It is completely free with no sign-up, no download and no usage limit. Everything is calculated in your browser, so the numbers you type never leave your device.
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.