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Free block paving calculator
Block paving calculator: blocks, sand, sub-base, edging and haunching
Measure the area, pick driveway or patio, the block and the pattern, and see the blocks, sub-base, laying sand, jointing sand, edging, haunching concrete and drainage to order. 200 × 100 blocks are 50 to the square metre, a drive gets 150mm of Type 1 at 2.1 tonnes per compacted cubic metre, permeable paving goes on open-graded Type 3, and the edge restraint sits on a proper concrete bed and haunch, about 0.03m³ a metre, not half a bag of Postcrete.
What you need
Blocks
- Blocks 200 × 100
- 1760 blocks50 per m² with the joint, plus 10% for cutsmaterialcalculator block paving; Marshalls
- Area to order
- 35.2 m²60mm blocks; packs are sold by the m², so divide by the pack
Sub-base and sand
- MOT Type 1 sub-base
- 11.09 tonnes150mm compacted at 2.1 t/m³ plus 10%, 0.35 t per m², or 14 bulk bags (~800 kg). Whack it in 75mm layersMarshalls how to lay; tradecalculator Type 1
- Sharp sand laying course
- 4 bulk bags (~800 kg)2.82 tonnes: 50mm loose, about 35mm once compacted, plus 10%Marshalls; Brett laying guide
- Kiln-dried sand
- 5 × 25kg bags3.5kg per m² brushed into the joints; top up after the first rainmaterialcalculator
- Geotextile membrane
- 1 × 1m × 50m rollsunder the sub-base to keep it out of the soil
Edging
- Edging run
- 24.0 mfull perimeter; take off any edge against the house
- Soldier course blocks
- 252 blocks10 per metre laid on edge, plus 5%; on top of the count above
- Haunching concrete (C20-type, or 1:6 ballast)
- 0.72 m³0.03m³ a metre: a 100mm bed and a haunch to half the block height, 75mm wide on a path or 100mm on a driveMarshalls; Brett; Pavingexpert edgings
- As bags: pre-mixed concrete
- 72 × 20kg bagsabout 0.01m³ a bag; not Postcrete, which is a fence-post product
- Or site mix: cement
- 9 × 25kg bagswith 2 bulk bags (~800 kg) of all-in ballast (1.26 tonnes) at 1:2:4tradecalculator, concretemath mix ratios
Drainage
- Linear drainage channel
- 4 × 1m lengthsacross the 4.0m where the paving meets the building
- Channel end caps and outlet
- 1 kit
- Fall
- 133.3 mmover the 8m run at 1:60, away from the house and 150mm below the DPCMarshalls: 1cm per 60cm
Dig
- Excavation
- 8.32 m³260mm deep: 150mm sub-base, 50mm sand and 60mm blocks. Use the hardcore calculator for the muck away and skips
- Block paving sealer
- 2 × 5L tinsoptional, about 25m² a tin; not for permeable paving
- Paved area
- 32.0 m²
Round up to whole packs and bags. Figures include the wastage you chose and match TradeCalc in the app.
For block pavings: turn this into a quote
In the app, TradeCalc hands these quantities straight to ProQuote with your regional material prices, and the customer gets a branded PDF. Free to download.
Or claim your free profile link nowHow the maths works
- Blocks per square metre come from the size with the joint (materialcalculator): 50 for 200 × 100, 26 for 240 × 160 Tegula-size, 77 for 200 × 65 cobbles, 44 for 150 × 150. Tumbled three-size mixes are sold by the m² so you get packs. Cuts add 5% for stretcher bond, 8% for basketweave, 10% for herringbone and another 5% on a circle (materialcalculator; Marshalls say add 10%).
- The sub-base is MOT Type 1 at 150mm compacted under a driveway or 100mm under a patio or path (Marshalls; tradecalculator), at 2.1 tonnes per compacted m³ plus 10%, the same figure as the hardcore calculator: 0.35 tonnes per m² at 150mm, so a bulk bag of about 800kg does roughly 2.3m². Permeable paving goes on open-graded Type 3 instead. A geotextile goes under it in 50m rolls.
- The laying course is 50mm of damp sharp sand, screeded off and compacting to about 35mm (Marshalls; Brett), at 1.6 tonnes per m³ plus 10%. Permeable blocks go on 6mm grit and are jointed with 2 to 6mm grit. Jointing is kiln-dried sand at 3.5kg per m² in 25kg bags.
- Edge restraint is the full perimeter unless you enter your own run: a soldier course of the same blocks at 10 a metre on edge, 200mm kerb units, or 915mm concrete path edgings, all plus 5%. Every edging sits on a 100mm concrete bed and is haunched to half the block height, 75mm wide on a path and 100mm on a drive (Marshalls; Brett; Pavingexpert), which is about 0.03m³ of C20-type or 1:6 ballast concrete a metre. That is 3 bags of pre-mixed concrete or, for a site mix, 12 bags of cement and 1.75 tonnes of ballast per m³. Postcrete is a fence-post product and half a bag a metre is 6 to 7 times short.
- A linear drainage channel runs across the width where the paving meets the building, with one kit of end caps and outlet. The paving falls away from the house at 1:60 (Marshalls: 1cm per 60cm) and finishes 150mm below the DPC.
- The dig is the sub-base plus 50mm of sand plus the block thickness: 60mm blocks for a drive, 50mm for a patio, 80mm for heavy vehicles. Sealer is optional on a driveway at about 25m² a tin, and not used on permeable paving.
Worked example
An 8m × 4m driveway in 200 × 100 blocks laid herringbone is 32m². With 10% for cuts that is 35.2m² or 1,760 blocks, on 11.09 tonnes of Type 1 (14 bulk bags) and 4 bulk bags of sharp sand, with 5 bags of kiln-dried sand, a 24m soldier course of 252 blocks on 0.72m³ of haunching concrete (72 bags, or 9 bags of cement and 2 bulk bags of ballast), 4 lengths of drainage channel and 2 tins of sealer. The dig is 260mm deep, 8.32m³.
Questions people ask
How many block paving blocks per square metre?
50 for the standard 200 × 100mm block including a 3mm joint. 240 × 160 Tegula-size blocks are 26, 200 × 65 cobbles about 77 and 150 × 150 about 44. Tumbled three-size mixes are sold by the square metre because the count depends on the mix, with packs of about 9m².
How much sub-base do I need for a driveway?
150mm of compacted MOT Type 1 under a drive, 100mm under a patio or path, laid and whacked in 75mm layers (Marshalls). At 150mm that is 0.35 tonnes per m² including 10%, so a bulk bag of about 800kg covers roughly 2.3m². On soft clay or for anything heavier than a car go to 200mm. Permeable paving uses open-graded Type 3 so water can get through.
How do I concrete in the edging?
Every edge restraint, whether a soldier course, a kerb or a path edging, needs a 100mm concrete bed with a haunch up the back to at least half the block height, 75mm wide on a path and 100mm on a drive. That is about 0.03m³ of concrete per metre, C20-type or 1:6 cement:ballast, so a 24m run is around 0.72m³: 72 bags of pre-mixed concrete or 9 bags of cement and a couple of bulk bags of ballast. Postcrete is for fence posts, and half a bag a metre is nowhere near enough.
Herringbone or stretcher bond?
Herringbone at 45° or 90° locks the blocks together and is the right choice for anything a car drives on. Stretcher bond looks neat on a path or patio and wastes fewer blocks, but can creep under turning wheels. Basketweave is somewhere between.
Do I need planning permission for a block paved driveway?
In England, a new or replacement front drive over 5m² needs permission unless the water drains to a permeable surface, a lawn or a border, or the paving itself is permeable. Permeable blocks on Type 3 and grit are one way round it; check with your council.
How much does block paving cost per m²?
It depends on the block, how much digging out there is and where you are. Use these quantities to check what a quote includes, look at the driveway cost guide, and get two or three quotes.
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