Soil Volume to Weight Calculator
Enter your soil volume and select the moisture condition to get an estimated weight in pounds and kilograms. Soil weight varies significantly depending on how wet or dry it is — this calculator shows you a realistic range rather than a single fixed number.
You bought a bag of soil. It says 50 liters on the front. Now you need to know how much it actually weighs — either to check your vehicle’s load limit, figure out a delivery, or just plan around what you can physically carry.
That’s what this calculator is for.
Put in your volume in liters. Pick your soil type. Get the weight back in pounds or kilograms. Done.
Why You Can’t Just Guess Soil Weight from Volume
This is the part that trips most people up.
Liters measure space. Kilograms and pounds measure mass. The two don’t convert at a fixed rate — not for soil, anyway. A liter of water always weighs 1 kg. Soil doesn’t work that way.
The weight of a liter of soil depends on what’s in it. Dry topsoil is lighter. Wet topsoil is heavier. Sandy soil sits at a different density than clay. Potting mix — which is mostly organic matter and perlite — weighs noticeably less than garden topsoil for the same volume.
So when someone asks how many pounds is 50 liters of soil, the honest answer is: it depends on the type and moisture level. Dry topsoil at 50 liters comes out around 55–65 lbs. Wet or compacted soil at the same volume can push past 80 lbs.
That’s a big range. The calculator accounts for it.
How Much Does a Litre of Soil Weigh?
As a general rule:
- Dry topsoil: roughly 1.1 to 1.3 kg per liter (about 2.4 to 2.9 lbs per liter)
- Moist topsoil: roughly 1.3 to 1.5 kg per liter (about 2.9 to 3.3 lbs per liter)
- Potting mix / compost: roughly 0.4 to 0.7 kg per liter (much lighter — lots of air and organic matter)
- Clay-heavy soil: can reach 1.6 kg per liter or more when wet
These are working estimates, not lab numbers. Real soil varies. But for planning a delivery, checking a load, or just figuring out if you can lift that bag — these ranges get you close enough.
Common Bag Sizes Converted
Most people searching for this just want a quick answer for a specific bag size. Here are the most commonly looked-up conversions using average moist topsoil density:
| Bag Volume | Approx. Weight (lbs) | Approx. Weight (kg) |
|---|---|---|
| 20 liters | 28–32 lbs | 13–15 kg |
| 21 liters | 30–35 lbs | 14–16 kg |
| 25 liters | 35–40 lbs | 16–18 kg |
| 28 liters | 39–45 lbs | 18–20 kg |
| 28.3 liters | 39–46 lbs | 18–21 kg |
| 30 liters | 42–48 lbs | 19–22 kg |
| 40 liters | 55–65 lbs | 25–29 kg |
| 42 liters | 58–68 lbs | 26–31 kg |
| 42.5 liters | 59–69 lbs | 27–31 kg |
| 50 liters | 70–85 lbs | 32–38 kg |
| 56 liters | 78–94 lbs | 35–43 kg |
| 56.6 liters | 79–95 lbs | 36–43 kg |
| 60 liters | 84–100 lbs | 38–45 kg |
| 80 liters | 110–132 lbs | 50–60 kg |
| 84.9 liters | 118–141 lbs | 53–64 kg |
| 85 liters | 119–142 lbs | 54–64 kg |
| 100 liters | 140–165 lbs | 63–75 kg |
| 750 liters | 1,050–1,230 lbs | 475–560 kg |
These figures assume standard moist garden topsoil. For potting mix, expect roughly 40–60% of these weights. For wet clay soil, expect the higher end or beyond.
Liters to kg — Soil Conversion Explained
Converting soil liters to kg is straightforward once you fix a density figure. Whether you call it liter to kg soil, litre to kg soil, or just l to kg soil — it’s all the same formula.
Weight (kg) = Volume (liters) × Density (kg/L)
For typical moist topsoil, density sits around 1.3–1.5 kg per liter. So:
- 50L soil in kg → 50 × 1.3 = 65 kg (dry end) up to 50 × 1.5 = 75 kg (moist)
- 100L of soil in kg → roughly 130–150 kg
- 60L of soil in kg → roughly 78–90 kg
- 40L soil in kg → roughly 52–60 kg
- 25L soil to kg → roughly 33–38 kg
- 20L soil in kg → roughly 26–30 kg
For potting mix, use a density of around 0.5–0.6 kg/L instead. A 32-quart bag of potting soil (roughly 30 liters) typically weighs only around 15–20 lbs — much lighter than the same volume of garden topsoil. If you’re wondering how much a 32-quart bag of potting soil weighs, that’s your number: usually 15–20 lbs depending on the brand and moisture.
The calculator above handles all of this automatically. Pick your soil type and it adjusts the density for you.
Liters to Pounds — Quick Reference
For US buyers working in pounds, here are the key conversions using moist topsoil:
- 21 liters of soil to pounds → roughly 60–70 lbs (same answer whether it’s soil or dirt)
- 25 liters of soil to pounds → roughly 72–82 lbs
- 28 liters of soil to pounds → roughly 80–92 lbs
- 28.3 liters of soil to pounds → roughly 81–93 lbs
- 42 liters of soil to pounds → roughly 120–138 lbs
- 42.5 liters of soil to pounds → roughly 122–140 lbs
- 50 liters of soil to pounds → roughly 143–165 lbs
- 56 liters of soil to pounds → roughly 160–185 lbs
- 56.6 liters of soil to pounds → roughly 162–187 lbs
- 85 liters of soil to pounds → roughly 243–280 lbs
- 84.9 liters of soil to pounds → roughly 243–280 lbs
These are real-world working numbers. Not lab values. Use them for planning, not engineering.
What Affects Soil Weight the Most?
Three things move the number more than anything else.
Moisture. Wet soil is dramatically heavier than dry. A 50-liter bag of topsoil fresh from outdoor storage after rain can weigh 20–30% more than the same bag kept indoors and dry. This is the biggest variable of all.
Soil type. Sandy soil drains fast and tends to be lighter. Clay holds water and gets very heavy very quickly. Standard topsoil sits somewhere in between.
Organic content. Potting mix, compost, and peat-heavy blends are much lighter per liter than mineral soil. That’s why a 50-liter bag of potting mix feels nothing like a 50-liter bag of topsoil from a garden center.
If you’re lifting bags manually, always assume the heavier end of the range. Backs don’t care about averages.
FAQs
How many pounds is 56.6 liters of soil?
A 56.6-liter bag of topsoil (the equivalent of a 2.0 cu. ft. bag) weighs approximately 162–187 lbs depending on moisture. Dry topsoil comes in at the lower end; wet or dense soil pushes toward the higher end.
How many pounds is 56 liters of soil?
Very close to 56.6L — roughly 160–185 lbs for standard moist topsoil. The small volume difference barely changes the result.
How many pounds is 28 liters of soil?
A 28-liter bag weighs approximately 80–92 lbs for moist garden topsoil. Potting mix at the same volume would be considerably lighter — around 30–40 lbs.
How many pounds is 42 liters of soil?
Roughly 120–138 lbs for standard moist topsoil. For 42.5 liters the number is almost identical — 122–140 lbs.
How many pounds is 21 liters of dirt?
About 60–70 lbs for typical moist topsoil or dirt. Same answer whether you call it soil or dirt — the density is the same.
How much does 50 liters of soil weigh?
Roughly 65–75 kg (143–165 lbs) for standard moist topsoil. Potting mix at 50 liters weighs considerably less — around 25–30 kg.
How many kg is 50 litres of soil?
Approximately 65–75 kg for garden topsoil. For lighter potting mixes, expect closer to 25–35 kg for the same volume.
How heavy is 100 liters of soil?
Around 130–150 kg for typical moist topsoil. That’s roughly the weight of a large bulk sack at the lighter end.
Can I convert liters to kg directly for soil?
Not at a fixed rate — you need a density figure first. For a quick estimate, multiply your liters by 1.3 for dry topsoil or 1.5 for moist. For potting mix, use 0.5.
When to Use Other Calculators
This soil weight calculator answers one question: how heavy is this volume of soil?
If you need to figure out how many bags cover your garden bed, use the bags of topsoil calculator.
If you’re working out total volume for a project in cubic yards, start with the topsoil calculator.
Need delivery or truckload planning? The truckload calculator has that covered.
Right tool, right question. That’s all it takes.
Daniel
Founder & Editor – TopSoilCalcOnline.com
Daniel is the founder and primary editor of TopSoilCalcOnline.com, a practical resource built to help homeowners, landscapers, and contractors accurately calculate topsoil, compost, and soil mix requirements. With hands-on experience in lawn preparation, raised beds, topdressing, and bulk soil planning, Daniel focuses on turning complex volume calculations into simple, reliable tools. Every calculator and guide on this site is designed to reduce material waste, prevent over-ordering, and help users plan landscaping projects with confidence and precision.