What is topdressing a lawn?

Topdressing is the application of a thin layer of material — usually a sand and compost mix or screened topsoil — over an existing lawn. It improves soil structure, levels uneven surfaces, reduces thatch breakdown, and encourages a denser, healthier sward.

How much topdressing do I need per square metre?

Application depth depends on the job. A 3mm compost roller pass uses around 3 litres per m². A standard levelling application at 5mm uses 5 litres per m². A heavy renovation at 8mm uses 8 litres per m². You must still be able to see grass blades after application — never smother the lawn.

When should I topdress my lawn?

Topdress when grass is actively growing — spring and early autumn are ideal. Avoid topdressing in summer drought, waterlogged conditions, or during winter dormancy. The grass needs to be able to grow up through the material quickly.

Can I topdress and overseed at the same time?

Yes — topdressing and overseeding work very well together. Apply a Pre-Seeder fertiliser first, overseed, then apply a light topdressing at 3-5mm to help retain moisture and improve seed-to-soil contact.

How accurate is this topdressing calculator?

This calculator gives guidance estimates based on your lawn area and chosen application depth. Actual requirements may vary for uneven lawns with humps, dips, and hollows which will need more material in low areas. Different topdressing materials also have varying densities so always check supplier recommendations. It is better to have a little extra than to run short mid-job.

Topdressing Calculator

Draw your lawn on the map or enter dimensions manually
Get accurate estimates for how much topdressing material you need

Find & Draw Your Lawn

Search for your address, then draw your lawn boundary on the satellite view

How to Measure Your Lawn

Search for your address above
Click "Start Drawing" below
Click points around your lawn boundary — add as many as you need for any shape
When finished, click "Finish Drawing" or click back on the first green dot to close the shape

Works with L-shapes, curved borders, any shape! Draw multiple areas for front and back gardens.

Click on the map to place your first point

Total: 0 m²

Or Enter Dimensions Manually

Length (metres)

Width (metres)

Keep Your Lawn Looking Its Best

Quantities update automatically for your exact lawn area.

Spring Starter Plus

Wake up your lawn after winter with the perfect spring blend.

Shop Now

Seaweed Lawn Booster

Natural seaweed extract to boost roots and support healthy recovery.

Shop Now

Autumn Lawn Builder

Root-strengthening nutrients to prepare your lawn for winter.

Shop Now

Pre-Seeder Fertiliser

Topdressing often goes hand in hand with overseeding. Get the nutrients in first.

Shop Now

Green Shot Iron

Instant green-up, moss control and hardening off — year-round.

Shop Now

Browse All Products

See our full range of fertilisers, treatments and lawn care products.

View All

Topdressing Calculator

Based on your lawn measurements

Your Lawn Area

square metres

Select Application Depth

3mm

Compost roller

5mm

Levelling

8mm

Heavy renovation

You'll Need Approximately

0 litres

of topdressing material

Volume in cubic metres 0 m³

Approx. weight (dry) 0 kg

Bags needed by size:

10 litre bags 0 bags

30 litre bags 0 bags

40 litre bags 0 bags

50 litre bags 0 bags

25kg bags 0 bags

Bulk bags (~900L)* 0 bags

*"Ton bags" rarely contain a full tonne — typically 800–1000 litres

Cost Estimator

Enter your bag size and price to calculate total cost

Bag size (litres)

Price per bag (£)

Important — Please Read

This is an estimate for guidance only — actual requirements may vary
Uneven lawns with humps, dips, and hollows will need more material in low areas
Different topdressing materials have varying densities — always check supplier recommendations
Better to have a little extra than to run short mid-job

Application Tips

Apply when grass is actively growing (spring or early autumn). Spread evenly and work into the lawn with a stiff brush or rake. Don't smother the grass — blades should still be visible after application.

Understanding Topdressing

Types of Topdressing

Topdressing comes in different types including: sand and soil mix (typically 70/30), compost, and loam or screened topsoil. Learn more in our guides to fixing a bumpy lawn and levelling your lawn like a pro.

Common Bag Sizes

Bagged topdressing (compost, soil, screened topsoil) typically comes in: 10L, 25L, 40L, 50L or 25kg bags. Bulk "ton bags" rarely contain a full tonne — they're usually 800–1000 litres, so always check the actual volume or weight.

When to Apply

Best applied in spring (April–May) or early autumn (September) when grass is actively growing. Avoid applying when the ground is frozen, waterlogged, or during drought conditions when grass is dormant.

Getting It Right

Spread evenly using a shovel and work into the lawn with a stiff brush or lute. For compost and soil/loam, a compost roller can help work it in — but don't use a roller on sand. The grass blades should still be visible after application.

Topdressing Calculator

Topdressing Calculator

Topdressing Calculator

Find & Draw Your Lawn

How to Measure Your Lawn

Or Enter Dimensions Manually

Keep Your Lawn Looking Its Best

Topdressing Calculator

Cost Estimator

Important — Please Read

Application Tips

Understanding Topdressing

Types of Topdressing

Common Bag Sizes

When to Apply

Getting It Right

More Free Tools

Shop the look

Choose options

Edit option

Back In Stock Notification

Terms & conditions