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Soil Mix Calculator

Calculate custom soil and potting mix ratios by plant type. Get exact amounts for peat, perlite, compost, and amendments.

Inputs

gal
%

Used only with Custom Mix

%

Used only with Custom Mix

%

Used only with Custom Mix

Results

Peat / Coir

2.0 gal

Perlite

1.3 gal

Compost

1.8 gal

Recommended AmendmentsAdd slow-release fertilizer and mycorrhizae
Estimated Dry Weight22.5 lbs

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Tips

1
Succulents need 50%+ perlite for fast drainage. Tropicals prefer moisture-retentive mixes.
2
Always moisten peat moss before mixing — dry peat is hydrophobic and hard to wet evenly.

Open formula

Component (gal) = Container Volume × Component%
Weight ≈ Volume × Mix Density

Calculates component volumes from percentage ratios for the target container size. Includes plant-type presets for common mixes.

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