Cubic Metres Bark Chippings To Tonnes Converter
Convert bark chippings volume into tonnes for paths, play surfaces, borders and weed-suppressing layers, with coverage depth, moisture and bag-count guidance.
Chippings Volume
Bark Chippings Result
Bark chippings are usually bought by volume. Tonnes are useful for transport and handling, but supplier bag volume is often the better ordering figure.
What This Bark Chippings Converter Does
This converter estimates the weight of bark chippings from cubic metres or from area and depth. It is intended for garden borders, informal paths, play surface topping, shrub beds and decorative ground cover. The page gives tonnes, kilograms, rounded bag count and a cost line, but it keeps volume visible because bark is usually sold by litres, cubic metres or nominal bulk bag volume.
Bark chippings are very different from stone aggregate. They are light, fibrous, full of voids and sensitive to moisture. A dry cubic metre may be easy to move; a wet cubic metre can be awkward and much heavier. That is why the density choices are lower than for gravel or sand.
Formula Used
Volume from area = area x depth in metres. Base tonnes = cubic metres x bulk density. Order tonnes = base tonnes x allowance. Bulk bags = order tonnes divided by bag weight, rounded up.
The weight result is a planning estimate. If your supplier sells by volume, keep the cubic metre result as the main buying figure and use tonnes for delivery, lifting and vehicle payload checks.
Depth And Use Guide
| Use | Common depth | Practical note |
|---|---|---|
| Decorative border top-up | 30 to 50 mm | Good where an older layer already exists. |
| Weed-suppressing layer | 50 to 75 mm | Prepare soil and remove persistent weeds first. |
| Informal path | 50 to 100 mm | Edging helps keep chippings in place. |
| Play surfacing | Follow product guidance | Safety surfacing depends on product, depth and fall height. |
Worked Examples
Border Top-Up
20 m2 at 50 mm is 1.0 m3. At 0.25 t/m3, that is about 0.25 tonnes before allowance. With 12% extra, the order weight is 0.28 tonnes.
Deeper Path
15 m2 at 80 mm is 1.2 m3. The volume looks small, but it may still fill several large bags because bark is bulky.
Wet Bark Delivery
Using 0.32 t/m3 for damp bark raises a 1 m3 load to 0.32 tonnes before allowance. This matters when lifting, barrowing or collecting.
Measuring A Bark Area
Split curved beds into smaller rectangles and triangles, then add the areas. For a border around shrubs, measure the area actually covered rather than the whole bed if large plants occupy space. Use finished depth, not the depth of a loose pile before raking. Bark settles after rain and foot traffic, so a modest allowance is usually sensible.
Keep chippings away from woody stems and building vents. Around plants, leave a small clear ring so moisture is not held directly against stems. For paths, edging, membrane choice and drainage can matter more than the weight calculation.
Ordering Notes
- Check whether the supplier sells by litre, m3, loose load or bulk bag.
- Light bark products may have no reliable tonne figure on the listing.
- Wet material can exceed the handling weight expected from dry density.
- Play-grade bark may have its own depth and maintenance requirements.
- Top up after settling rather than buying an excessive first layer.
Paths, Edges And Membranes
For paths, the volume calculation is only part of the job. Edging helps keep chippings from spreading into lawns or beds. A membrane can reduce mixing with soil, but it may not suit every planting area because it can affect future digging and soil improvement. If the path carries wheelbarrows, consider a firmer base under the bark so the surface does not rut quickly.
Where chippings are used under play equipment, follow the product’s safety guidance rather than only a volume estimate. The required depth can depend on the product and use. Keep the product name and batch note for later top-ups.
FAQs
How many tonnes are in one cubic metre of bark chippings?
A typical planning estimate is about 0.25 tonnes per cubic metre, but dry and wet bark can differ widely.
Should I buy bark by tonne or cubic metre?
Most garden bark is easier to buy by volume. Tonnes are mainly useful for transport and payload checks.
Does bark settle after laying?
Yes. Bark can settle after rain, raking and foot traffic, so an allowance or later top-up can be helpful.
Can I use this for play bark?
Use it for quantity planning only. Follow the product guidance for play depth and maintenance.
Why is bark so much lighter than gravel?
Bark has lower particle density and many air voids, so a cubic metre weighs far less than stone.
Sources
- Royal Horticultural Society. (2026). Mulches and mulching. RHS. https://www.rhs.org.uk/soil-composts-mulches/mulching
- British Standards Institution. (2018). BS EN 1177: Impact attenuating playground surfacing. Methods of test for determination of impact attenuation. BSI. https://knowledge.bsigroup.com/
- Forest Research. (2025). Wood products, bark and biomass information. Forest Research. https://www.forestresearch.gov.uk/
- National Institute of Standards and Technology. (2008). Guide for the Use of the International System of Units (SI), Special Publication 811. NIST. https://www.nist.gov/pml/special-publication-811
