SettingsSettings for this calculationUS
Waste is set to 0% by hand. Pick a tier above to replace it, or keep your own figure.
The surface the product goes on: the whole slab to resurface, or the patches added together.
For a resurfacer, measure the slab you are covering, a driveway, a garage floor, a path. For patches, add up the area of each hole or spalled patch; where they differ a lot in depth, run the deep ones and the shallow ones separately and add the bags.
Tools needed: Tape measure
The depth of new material, averaged over the area: 5 mm (0.2 in) or 1/4 in (6.4 mm) at the openings.
For a resurfacing coat this is its finished thickness. For a patch it is the average depth of the hole, which is less than its deepest point when the edges are feathered out; probe or measure several points and average them. The page sets the depth beside the least and greatest depths below and flags it outside them.
Tools needed: Straightedge, Depth gauge or rule
What the bag's coverage line says one bag spreads over: 3.0 m² (32 sq ft) for ARDEX K 301, 16 sq ft (1.5 m²) for QUIKRETE Re-Cap.
Copy it with the depth it is stated at, from the bag or its data sheet. ARDEX K 301 gives about 3.0 m² (32 sq ft) at 5 mm (0.2 in) from a 25 kg (55 lb) bag; QUIKRETE Re-Cap about 16 ft² (1.5 m²) at 1/4 in (6.4 mm), or 65 ft² (6.0 m²) at 1/16 in (1.6 mm), from a 40 lb (18.1 kg) bag; ARDEX A 46 about 4 m² (43 sq ft) at 2 mm (0.08 in) from an 11 kg (24.3 lb) bag. Any of a maker's lines gives nearly the same yield, because the bag is a volume.
The depth on the same coverage line: 5 mm (0.2 in) for ARDEX K 301, 1/4 in (6.4 mm) for QUIKRETE Re-Cap.
The bag's yield is its stated area times this depth, and the page works in volume from there. Enter it exactly as printed beside the area, even where it differs from the depth you are laying.
The thinnest the maker allows: 2 mm (0.08 in) for ARDEX K 301, a 1/16 in (1.6 mm) feather edge for QUIKRETE Re-Cap.
Read it off the data sheet; it is the thinnest its maker's instructions allow. Patching products often feather further than a resurfacer will go: QUIKRETE's Vinyl Concrete Patcher to 1/16 in (1.6 mm), ARDEX A 46 from 2 mm (0.08 in).
The thickest the maker allows: 20 mm (0.79 in) for ARDEX K 301, 1/2 in (13 mm) for QUIKRETE Re-Cap.
Use the total depth the sheet allows. Some sheets set a limit on each layer as well: QUIKRETE builds Re-Cap up in layers no thicker than 1/4 in (6.4 mm), while ARDEX lays K 301 up to 20 mm (0.79 in) in one go and caps its combined layers there. A repair mortar goes deeper: ARDEX A 46 to 30 mm (1.18 in), and to 50 mm (1.97 in) in small, localised repairs with coarse aggregate added.
Mortar to add for the bucket's leavings, spills and hollows; it starts at 0, because no data sheet cited gives a figure.
ARDEX's and QUIKRETE's sheets set no over-order figure, so the page starts at none. A pitted or uneven slab swallows more in its low spots than its average depth suggests; allow for that from your own jobs.
Bags to buy
14 bags
Area times average depth gives the mortar the repair takes. Each bag yields what its coverage line prints, that area laid at that depth, and the count is the mortar, with any allowance added, divided by one bag's yield and rounded up to whole bags.
- Material to place
- 4.58 ft³
- Mortar from one bag
- 0.33 ft³
- Area one bag covers at the depth entered
- 16 ft²
They open the calculator with your figures already in it
Concrete Resurfacer and Patch Calculator: 14 bags — shown in imperial, US market. The link sets both, so the result they see is the one on your screen.
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How this was calculated
Formula source(s)
- ARDEX UK, ARDEX K 301 product data sheet (April 2025): a resurfacing mortar for exterior concrete such as driveways, garage floors, paths and patios; applied from 2mm to 20mm thick in a single application, the thickness of combined layers not to exceed 20mm; coverage approximately 1.6kg powder/m²/mm, i.e. approximately 3.0m² at 5mm thickness per 25kg bag
- QUIKRETE, Re-Cap Concrete Resurfacer (No. 1131) data sheet (revised January 2023): applied from a feather edge of 1/16 in to 1/2 in (1.6 mm to 13 mm), built up in layers each not exceeding 1/4 in (6.3 mm); one 40 lb bag covers approximately 16 ft2 (1.5 m2) at 1/4 in (6.3 mm), or approximately 65 ft2 (6.0 m2) at 1/16 in (1.6 mm)
- ARDEX UK, ARDEX A 46 product data sheet (June 2018): a rapid concrete repair mortar applied from 2mm to 30mm, and for localised small repairs up to 50mm thick, with coarse aggregate added for localised thicknesses over 20mm; an 11kg bag produces approximately 8 litres of mortar, approximately 4m² at 2mm
- QUIKRETE, Vinyl Concrete Patcher (No. 1133) data sheet (revised February 2022): troweled to a feather edge of 1/16 inch (1.6 mm); a 40 lb bag covers multiple applications for a total of 34 ft2 (3.1 m2) at 1/8 inch thickness; not intended for use as a coating or over large areas, which must be less than 2 ft2 (0.19 m2)
Inputs used
- Area to Resurface or Patch
- 220 sq ft
- Average Depth
- 0.25 in
- Coverage Area Printed on the Bag
- 16 sq ft
- Depth the Bag's Coverage Assumes
- 0.25 in
- Least Depth the Product Allows
- 0.06 in
- Greatest Depth the Product Allows
- 0.5 in
- Waste / Over-Order (%)
- 0
Intermediate steps
- Material to place
- 4.58 ft³
- Mortar from one bag
- 0.33 ft³
- Area one bag covers at the depth entered
- 16 ft²
Confidence note: Area times average depth gives the mortar the repair takes. Each bag yields what its coverage line prints, that area laid at that depth, and the count is the mortar, with any allowance added, divided by one bag's yield and rounded up to whole bags.
What this calculation does not cover
- The yield is the maker's statement for its own bag, mixed as its sheet says. A wetter or drier mix, or a different product, changes it; enter the coverage line printed on the bag being used.
- The depth is an average over the area entered. A worn slab is rarely even, and a patch feathered out to nothing at its edge holds less than its deepest point suggests; take depths at several points and average them, or split the repair into areas of like depth.
- The least and greatest depths are the maker's for its product, entered here; nothing on this page knows them for any other. Some makers set a limit on a single layer as well as on the total, and building up in layers is their instruction to follow.
- Whether the slab can be resurfaced at all is not in the arithmetic: unsound, cracked-through or moving concrete, a slab that heaves, and joints that must be carried up through the new surface are questions for the repair, not the quantity.
- Primers, bonding agents, the aggregate a repair mortar is bulked out with at depth, and the cleaning and preparation each sheet calls for are separate items.
Estimated cost — your price
This site holds no price list for this material — local prices vary too much to publish honestly. Enter your supplier's price and the result is costed with it.
Computed in your browser — nothing you enter is uploaded. Presented in US customary units and US trade terminology. Where a formula follows a published standard, that standard and its edition are cited beside it on this page; where none governs, the page says so. Local amendments override model codes — verify against the code in force where you build.
Sources checked 2026-10-05 · v1.0.0
Regulatory standards & verification citations4
- ARDEX UK, ARDEX K 301 product data sheet (April 2025): a resurfacing mortar for exterior concrete such as driveways, garage floors, paths and patios; applied from 2mm to 20mm thick in a single application, the thickness of combined layers not to exceed 20mm; coverage approximately 1.6kg powder/m²/mm, i.e. approximately 3.0m² at 5mm thickness per 25kg bag
- QUIKRETE, Re-Cap Concrete Resurfacer (No. 1131) data sheet (revised January 2023): applied from a feather edge of 1/16 in to 1/2 in (1.6 mm to 13 mm), built up in layers each not exceeding 1/4 in (6.3 mm); one 40 lb bag covers approximately 16 ft2 (1.5 m2) at 1/4 in (6.3 mm), or approximately 65 ft2 (6.0 m2) at 1/16 in (1.6 mm)
- ARDEX UK, ARDEX A 46 product data sheet (June 2018): a rapid concrete repair mortar applied from 2mm to 30mm, and for localised small repairs up to 50mm thick, with coarse aggregate added for localised thicknesses over 20mm; an 11kg bag produces approximately 8 litres of mortar, approximately 4m² at 2mm
- QUIKRETE, Vinyl Concrete Patcher (No. 1133) data sheet (revised February 2022): troweled to a feather edge of 1/16 inch (1.6 mm); a 40 lb bag covers multiple applications for a total of 34 ft2 (3.1 m2) at 1/8 inch thickness; not intended for use as a coating or over large areas, which must be less than 2 ft2 (0.19 m2)
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Tools and safety for this job
To place and finish concrete, erect formwork and saw-cut cured concrete. Generic types, no brands, no prices.
Protection this work requires
- Cutting or grinding concrete, masonry, screed, tile or fibre-cement board releases respirable silica: cut wet or extract at the tool, and wear a P2/N95 respirator at minimum — a nuisance dust mask does not filter it.
- Hardwood dust is a recognised carcinogen: extract at the tool and wear a P2/N95 respirator when cutting or sanding indoors.
- Wet cement and lime burn skin and eyes painlessly until the damage is done: waterproof gloves to EN 374, safety glasses whenever the mix can splash, and never kneel in wet mix in permeable trousers.
- Saws, grinders and breakers run above 85 dB, where hearing damage accumulates and does not recover: defenders or plugs for every cut, not just the long ones.
- Breakers and grinders cause permanent nerve damage: limit continuous trigger time, keep hands warm, and stop if fingers tingle or blanch.
- Boards, blocks and bagged material cause most lasting back injuries on small sites: two people or a lifter for full sheets, and never a bag on one shoulder up a ladder.
Show the 17 tools this job needsHide tools
Essential
Angle grinder
Bull float and edger
Circular saw
Claw hammer
Dust extractor or vacuum with a fine filter
Screed bar or rail
Shovel and spade
Spirit level
String line and pins
Tape measure
Wheelbarrow
Recommended
Chalk line
Cordless drill/driver
Floor or cut-off saw
Plate compactor
SDS rotary hammer
Optional
Power float
Also needed as materials: chalk refill, circular saw blades, cutting and diamond discs, diamond blades, drill and driver bits, SDS bits and chisels.
what each concrete tool is for, and the spec that decides which to buy where one does.