Quarts, liters and cubic feet on a soil bag: turning any label into cubic feet

Walk down the soil aisle and the labels change units from bag to bag. Small bags of potting mix are often sold in quarts, mulch and raised bed mix in cubic feet, and some bags add liters. The units come from the rules on how goods are sold. NIST Handbook 130, the model rule most states build on, says mulch must be sold by the cubic foot or cubic yard, or by the liter or cubic meter. Peat moss is sold by weight or by liters and cubic feet.

Source: NIST Handbook 130 (2026), Uniform Regulation for the Method of Sale of Commodities, checked October 11, 2026.

The calculators on this site give cubic feet for a bed or a pot, and bulk soil is priced by the cubic yard, which is 27 cubic feet. So the first job with any bag is to turn its label into cubic feet.

Source: MSU Extension P2301, mulches, checked October 9, 2026.

• 25.7 dry qtin one cubic footNIST Guide to the SI (SP 811), Appendix B.8 conversion factors, October 11, 2026
• 28.3 Lin one cubic footNIST Guide to the SI (SP 811), Appendix B.8 conversion factors, October 11, 2026
• 27 cu ftin one cubic yardMSU Extension P2301, mulches, October 9, 2026
• 16%more in a dry quart than a liquid quartNIST Guide to the SI (SP 811), Appendix B.8 conversion factors, October 11, 2026

To get cubic feet from quarts, divide by 25.7. From liters, divide by 28.3. To go the other way, multiply. NIST lists a dry quart as 1.101 liters and a liquid quart as 0.946 liters, so the quart on a potting mix bag is about a sixth bigger than the quart you know from the kitchen. If you read a bag as liquid quarts you'll undercount what's in it.

Source: NIST Guide to the SI (SP 811), Appendix B.8 conversion factors, checked October 11, 2026.

Worked with NIST's factors and rounded. Bag sizes are ones seen on maker pages, not product picks.

Source: NIST Guide to the SI (SP 811), Appendix B.8 conversion factors, checked October 11, 2026; Miracle-Gro Potting Mix product page, checked October 7, 2026; Kellogg Garden raised bed mix product page, checked October 6, 2026.

Labels round. One maker's raised bed soil page lists a 1.5 cubic foot bag as 40 quarts, which works out to 1.56 cubic feet. Another lists a 2 cu ft bag as 56.6 liters, which matches the factor exactly. When a bag shows two units, use the cubic feet.

Source: Miracle-Gro raised bed soil product page, checked October 6, 2026; Kellogg Garden raised bed mix product page, checked October 6, 2026; NIST Guide to the SI (SP 811), Appendix B.8 conversion factors, checked October 11, 2026.

1. 1

   Find the volume line

   Look for the net contents on the front of the bag, often near the bottom. Ignore the bag weight if it's printed too.

2. 2

   Turn it into cubic feet

   Quarts divided by 25.7, liters divided by 28.3. A 16 quart bag is 0.62 cubic feet.

   Source: NIST Guide to the SI (SP 811), Appendix B.8 conversion factors, checked October 11, 2026.

3. 3

   Price each cubic foot

   Divide the shelf price by the cubic feet. With made-up prices of $8 for 25 quarts and $12 for 2 cu ft, that's $8.23 and $6 a cubic foot.

4. 4

   Count the bags

   Divide the cubic feet your job needs by the bag's cubic feet and round up.

Past a certain size, bags stop being the cheap way. A cubic yard is 27 cubic feet, which is 13.5 bags of 2 cu ft or about 28 bags of 25 quarts. Handbook 130 says bulk topsoil, sand and rock are sold by the cubic yard or by weight, so a quote from a landscape yard will be in yards or tons. The bags or bulk guide walks through that comparison.

Source: MSU Extension P2301, mulches, checked October 9, 2026; NIST Handbook 130 (2026), Uniform Regulation for the Method of Sale of Commodities, checked October 11, 2026; NIST Guide to the SI (SP 811), Appendix B.8 conversion factors, checked October 11, 2026.