🌿 Mulch
🆓 Free
m³ / Bags / Tonnes
🌿 Mulch Calculator
Enter your garden bed dimensions and desired depth to instantly calculate cubic metres, number of bags, and total material cost. Add multiple beds to get a combined total, and compare the cost of bags versus bulk delivery to find the most economical option for your volume. Supports mulch, topsoil, compost, gravel, and sand.
🌿 Mulch / Fill Material Calculator
Material Type
Bed Shape
-
Total Volume Needed
🌱 Multiple Garden Beds
Add each bed or area to calculate combined total.
Bed / Area
L (m)
W (m)
Depth
🛒 When to Buy Bags vs Bulk
Bags vs Bulk Comparison
Bags are better when:
Volume under 1–2 m³
No vehicle/trailer for bulk delivery
Precise quantities needed
Easy access - no bulk truck access
Bulk (tonne bag / loose delivery) when:
Volume over 2 m³
Cost savings: bulk is 30–50% cheaper per m³
Large garden or multiple areas
Example: 3 m³ of mulch
Bags (70L at ₹350 each):
43 bags × ₹350 = ₹15,050
Cost per m³: ₹5,017
Bulk (₹3,500/m³ + ₹800 delivery):
3 m³ × 3,500 + 800 = ₹11,300
Cost per m³: ₹3,767
Saving with bulk: ₹3,750 (25%)
Run the calculator first to see your personalised comparison.
📐 Depth Guide & Coverage
Volume Formula
Volume (m³) = Area (m²) × Depth (m)
Depth in mm → divide by 1000 to get metres
50mm = 0.05m
Example: 6m × 2.5m bed, 50mm depth
Area = 6 × 2.5 = 15 m²
Volume = 15 × 0.05 = 0.75 m³
Bags needed = Ceil(Volume / Bag volume)
70L bags = 0.07 m³ each
Bags = Ceil(0.75 / 0.07) = 11 bags
1 m³ = 1000 litres = ~14 bags of 70L
1 tonne bag (bulk) ≈ 0.6–0.8 m³ (depending on material)
❓ Frequently Asked Questions
AI Garden Advisor - Coming Soon!
AI-powered garden bed planning, material recommendations and seasonal mulching schedules based on your climate and plant types.
⏳ Coming Soon - Stay Tuned!
Mulch Calculator - How Much Do You Need and What's the Best Way to Buy?
Ordering the wrong amount of mulch is one of the most common garden project mistakes. Too little and you need a second trip to the hardware store (often a different batch, sometimes a different shade). Too much and you're dealing with a heap of material you have nowhere to put. Getting the volume right before you order takes two minutes with this calculator.
Quick example: 3 garden beds - 4m×1.5m, 3m×2m, and 6m×1m - at 50mm (0.05m) depth. Total volume = (4×1.5×0.05) + (3×2×0.05) + (6×1×0.05) = 0.30 + 0.30 + 0.30 = 0.90 m³. At 70L bags: 0.90 ÷ 0.07 = 12.9 → 13 bags needed. Add 10% buffer = 14 bags.
Mulch Depth Guide - How Deep for Each Application
Recommended Depths
- New garden beds: 50–75mm. Establishes proper weed suppression and moisture retention.
- Annual top-up: 25mm. Refreshes decomposed mulch without over-applying.
- Heavy weed suppression: 75–100mm. High problem areas or pathways.
- Tree and shrub circles: 75mm. Keep 5–10cm clear of trunk/stem.
- Vegetable gardens: 50mm (don't let mulch touch plant stems).
How Much 1 m³ Covers
- At 25mm depth → covers 40 m²
- At 50mm depth → covers 20 m²
- At 75mm depth → covers 13.3 m²
- At 100mm depth → covers 10 m²
- 1 m³ ≈ 14 × 70L bags or 10 × 100L bags
- Always add 10% buffer to your calculated volume
Bags vs Bulk - When Each Option Makes More Sense
The crossover point between bags and bulk delivery depends on the price per m³ in your area, but there are practical considerations beyond price:
- Under 1 m³ (up to ~14 bags): Bags are almost always more convenient - no delivery booking, no access requirements, easy to handle one at a time.
- 1–3 m³: Compare carefully. Calculate bag cost (price per bag × bags needed) against bulk delivery (per m³ price × volume + delivery fee). Bulk often wins here but the difference varies.
- Over 3 m³: Bulk almost always wins on price - typically 25–40% cheaper per m³ than bagged equivalents. However, you need good vehicle access to the delivery point, and someone needs to be home to receive it.
- Large landscape jobs: Consider tonne bags (bulk bags) - 800–1000kg each, typically 0.5–0.7 m³ of loose material. Delivered on a pallet, manageable with a small forklift attachment or strong team.
Mulch vs Topsoil vs Compost - Which Do You Actually Need?
These three materials are often confused but serve very different purposes:
- Mulch (bark, wood chips, straw): Goes on top of the soil surface. Suppresses weeds, retains moisture, regulates soil temperature, and improves appearance. Does not significantly add nutrients - it sits on top, not in the growing zone. Best for established beds, tree circles, and pathways.
- Topsoil: The upper layer of mineral soil with organic matter. Used to fill raised beds, level lawn areas, establish new growing areas, or improve thin soil. Mixed into or applied as a growing medium - not a surface covering. Essential when building new garden beds from scratch.
- Compost: Decomposed organic matter - the richest in nutrients of the three. Best dug into existing soil before planting to improve fertility and structure. Can also be used as a surface mulch (breaks down quickly). Ideal for vegetable gardens and newly established beds.
- Gravel/pebble: Decorative and permanent. Does not decompose, so no topping up required. Good for dry gardens, succulents, and areas where organic mulch would mat down. Does not improve soil - it just covers it.