Measure the area
Multiply length by width. For circles, measure the diameter; for irregular beds, split the area into simple shapes.
Free UK garden calculator
Buy the right amount of mulch, first time.
Calculate exactly how much bark, wood chip or compost your garden needs—in litres, cubic metres, bags and pounds.
✓ UK bag sizes✓ Instant results✓ No sign-up
1 m³equals 1,000 litres
or twenty 50L bags
or twenty 50L bags
MULCH ESTIMATOR
FREEHow much do you need?
YOUR ESTIMATE
0.825 m³825 litres including 10% extra
Area15 m²
60L bags14
Est. cost£119
We round bags up so you are not caught short. Base quantity before allowance: 750 litres.
🌿 Flower beds
🌳 Trees & borders
🥕 Vegetable plots
🪵 Paths & play areas
THE SIMPLE METHOD
How to calculate mulch
Three measurements are all you need. Keep every measurement in metres for the simplest calculation.
Choose a depth
Use 5 cm for a lighter top-up or around 7.5 cm when stronger weed suppression is the goal.
Round bags up
Add an allowance for settling, then divide litres by your bag size. Always round the final number up.
THE FORMULA
Area × depth = volume
For a 5 m × 3 m bed at 5 cm depth:
5m × 3m×0.05m=0.75m³=750L
DEPTH GUIDE
Choose the right mulch depth
These practical starting points suit common garden jobs. Product instructions and site conditions should always take priority.
UseTypical depthHelpful note
Flower beds & borders5–7.5 cmKeep clear of plant stems
Around trees & shrubs5–7.5 cmLeave a gap around trunks
Vegetable plots5–7.5 cmUse clean organic material
Garden paths7.5–10 cmCoarse chips settle less
Play areasSpecialist adviceFollow product safety guidance
MATERIAL GUIDE
Which mulch should you choose?
Bark chippings
Neat, durable and ideal for beds, borders and paths. Larger grades usually last longer.
Best for polished garden finishes →Garden compost
Feeds the soil as it breaks down and works particularly well around hungry plants.
Best for improving your beds →Wood chips
A practical choice for larger areas, informal paths and established trees or shrubs.
Best for larger projects →COMMON QUESTIONS
Mulch calculator FAQs
Quick answers for planning your next garden project with confidence.
How much mulch do I need?
Multiply the area in square metres by the mulch depth in metres. The result is cubic metres; multiply by 1,000 for litres. Our calculator does this and rounds bag quantities up for you.
How deep should mulch be in the UK?
For most established beds, 5–7.5 cm is a useful starting range. Coarse wood chips may need a deeper layer, while compost used as a surface mulch is often applied around 5 cm deep.
How many 50 litre bags are in a cubic metre?
There are 20 × 50 litre bags in one cubic metre. Allowing 10% extra means ordering 22 bags.
Should I add extra for settling and uneven ground?
Yes. Ten percent is sensible for a typical level bed. Consider 15–20% for uneven areas, deep wood chip layers or material that settles noticeably.
Can I put mulch directly over weeds?
Remove established perennial weeds first. A suitable mulch layer can then reduce new weed growth, but it will not reliably kill every existing weed or root.
Measure once. Order right.
Get your mulch estimate in less than a minute.
Use the free calculator →