Free · 4 explainers · 179 worked examples

Guides & worked examples

Start with an explainer if you want to know what a mix ratio means or how bag yields are worked out. Below them, common jobs already calculated: the volume in cubic yards and metres and the bag count in every size, plus which mix ratio each application calls for. Every number comes from the same formulas the calculators use.

Explainers Slab Footing Column Post holes Steps Curb Mortar Concrete mix Render Screed Grout

4 guides

Explainers

The questions behind the numbers - what a mix ratio means, how bag yields work, and which material a job actually wants.

Concrete Mix Ratios Explained: What 1:2:4 Actually Means6 min readWhat the numbers in a concrete mix ratio mean, how nominal M-grades like 1:2:4 and 1:1.5:3 compare, and where nominal mixing stops and design mixes begin.How Many Bags of Concrete Do I Need? The Maths Behind the Answer6 min readHow bag yield works, how to get from dimensions to cubic feet to a bag count, why 80 lb bags yield 0.60 ft3, and when bags stop being the cheap option.Mortar Types M, S, N, O and K Explained6 min readWhat ASTM C270 mortar types M, S, N, O and K are for, their cement-lime-sand ratios and strengths, and why the strongest mortar is usually the wrong one.Concrete vs Mortar vs Grout vs Screed vs Render6 min readFive cement-based materials that get confused daily: what each one is proportioned from, what job it does, and why swapping one for another fails.

93 guides

Slab

Patios, floors, driveways and pads at 4, 5 and 6 inches thick.

Concrete for a 4×4 ft slab, 4 in thick0.2 yd³9 × 80 lb bags Concrete for a 4×4 ft slab, 5 in thick0.25 yd³12 × 80 lb bags Concrete for a 4×4 ft slab, 6 in thick0.3 yd³14 × 80 lb bags Concrete for a 4×8 ft slab, 4 in thick0.4 yd³18 × 80 lb bags Concrete for a 4×8 ft slab, 5 in thick0.49 yd³23 × 80 lb bags Concrete for a 4×8 ft slab, 6 in thick0.59 yd³27 × 80 lb bags Concrete for a 5×5 ft slab, 4 in thick0.31 yd³14 × 80 lb bags Concrete for a 5×5 ft slab, 5 in thick0.39 yd³18 × 80 lb bags Concrete for a 5×5 ft slab, 6 in thick0.46 yd³21 × 80 lb bags Concrete for a 6×6 ft slab, 4 in thick0.44 yd³20 × 80 lb bags Concrete for a 6×6 ft slab, 5 in thick0.56 yd³25 × 80 lb bags Concrete for a 6×6 ft slab, 6 in thick0.67 yd³30 × 80 lb bags Concrete for a 6×8 ft slab, 4 in thick0.59 yd³27 × 80 lb bags Concrete for a 6×8 ft slab, 5 in thick0.74 yd³34 × 80 lb bags Concrete for a 6×8 ft slab, 6 in thick0.89 yd³40 × 80 lb bags Concrete for a 8×8 ft slab, 4 in thick0.79 yd³36 × 80 lb bags Concrete for a 8×8 ft slab, 5 in thick0.99 yd³45 × 80 lb bags Concrete for a 8×8 ft slab, 6 in thick1.19 yd³54 × 80 lb bags Concrete for a 8×10 ft slab, 4 in thick0.99 yd³45 × 80 lb bags Concrete for a 8×10 ft slab, 5 in thick1.23 yd³56 × 80 lb bags Concrete for a 8×10 ft slab, 6 in thick1.48 yd³67 × 80 lb bags Concrete for a 8×12 ft slab, 4 in thick1.19 yd³54 × 80 lb bags Concrete for a 8×12 ft slab, 5 in thick1.48 yd³67 × 80 lb bags Concrete for a 8×12 ft slab, 6 in thick1.78 yd³80 × 80 lb bags Concrete for a 10×10 ft slab, 4 in thick1.23 yd³56 × 80 lb bags Concrete for a 10×10 ft slab, 5 in thick1.54 yd³70 × 80 lb bags Concrete for a 10×10 ft slab, 6 in thick1.85 yd³84 × 80 lb bags Concrete for a 10×12 ft slab, 4 in thick1.48 yd³67 × 80 lb bags Concrete for a 10×12 ft slab, 5 in thick1.85 yd³84 × 80 lb bags Concrete for a 10×12 ft slab, 6 in thick2.22 yd³100 × 80 lb bags Concrete for a 10×15 ft slab, 4 in thick1.85 yd³84 × 80 lb bags Concrete for a 10×15 ft slab, 5 in thick2.31 yd³105 × 80 lb bags Concrete for a 10×15 ft slab, 6 in thick2.78 yd³125 × 80 lb bags Concrete for a 10×20 ft slab, 4 in thick2.47 yd³112 × 80 lb bags Concrete for a 10×20 ft slab, 5 in thick3.09 yd³139 × 80 lb bags Concrete for a 10×20 ft slab, 6 in thick3.7 yd³167 × 80 lb bags Concrete for a 12×12 ft slab, 4 in thick1.78 yd³80 × 80 lb bags Concrete for a 12×12 ft slab, 5 in thick2.22 yd³100 × 80 lb bags Concrete for a 12×12 ft slab, 6 in thick2.67 yd³120 × 80 lb bags Concrete for a 12×14 ft slab, 4 in thick2.07 yd³94 × 80 lb bags Concrete for a 12×14 ft slab, 5 in thick2.59 yd³117 × 80 lb bags Concrete for a 12×14 ft slab, 6 in thick3.11 yd³140 × 80 lb bags Concrete for a 12×16 ft slab, 4 in thick2.37 yd³107 × 80 lb bags Concrete for a 12×16 ft slab, 5 in thick2.96 yd³134 × 80 lb bags Concrete for a 12×16 ft slab, 6 in thick3.56 yd³160 × 80 lb bags Concrete for a 12×20 ft slab, 4 in thick2.96 yd³134 × 80 lb bags Concrete for a 12×20 ft slab, 5 in thick3.7 yd³167 × 80 lb bags Concrete for a 12×20 ft slab, 6 in thick4.44 yd³200 × 80 lb bags Concrete for a 12×24 ft slab, 4 in thick3.56 yd³160 × 80 lb bags Concrete for a 12×24 ft slab, 5 in thick4.44 yd³200 × 80 lb bags Concrete for a 12×24 ft slab, 6 in thick5.33 yd³240 × 80 lb bags Concrete for a 14×14 ft slab, 4 in thick2.42 yd³109 × 80 lb bags Concrete for a 14×14 ft slab, 5 in thick3.02 yd³137 × 80 lb bags Concrete for a 14×14 ft slab, 6 in thick3.63 yd³164 × 80 lb bags Concrete for a 15×15 ft slab, 4 in thick2.78 yd³125 × 80 lb bags Concrete for a 15×15 ft slab, 5 in thick3.47 yd³157 × 80 lb bags Concrete for a 15×15 ft slab, 6 in thick4.17 yd³188 × 80 lb bags Concrete for a 16×16 ft slab, 4 in thick3.16 yd³143 × 80 lb bags Concrete for a 16×16 ft slab, 5 in thick3.95 yd³178 × 80 lb bags Concrete for a 16×16 ft slab, 6 in thick4.74 yd³214 × 80 lb bags Concrete for a 16×20 ft slab, 4 in thick3.95 yd³178 × 80 lb bags Concrete for a 16×20 ft slab, 5 in thick4.94 yd³223 × 80 lb bags Concrete for a 16×20 ft slab, 6 in thick5.93 yd³267 × 80 lb bags Concrete for a 16×24 ft slab, 4 in thick4.74 yd³214 × 80 lb bags Concrete for a 16×24 ft slab, 5 in thick5.93 yd³267 × 80 lb bags Concrete for a 16×24 ft slab, 6 in thick7.11 yd³320 × 80 lb bags Concrete for a 18×20 ft slab, 4 in thick4.44 yd³200 × 80 lb bags Concrete for a 18×20 ft slab, 5 in thick5.56 yd³250 × 80 lb bags Concrete for a 18×20 ft slab, 6 in thick6.67 yd³300 × 80 lb bags Concrete for a 20×20 ft slab, 4 in thick4.94 yd³223 × 80 lb bags Concrete for a 20×20 ft slab, 5 in thick6.17 yd³278 × 80 lb bags Concrete for a 20×20 ft slab, 6 in thick7.41 yd³334 × 80 lb bags Concrete for a 20×24 ft slab, 4 in thick5.93 yd³267 × 80 lb bags Concrete for a 20×24 ft slab, 5 in thick7.41 yd³334 × 80 lb bags Concrete for a 20×24 ft slab, 6 in thick8.89 yd³400 × 80 lb bags Concrete for a 20×30 ft slab, 4 in thick7.41 yd³334 × 80 lb bags Concrete for a 20×30 ft slab, 5 in thick9.26 yd³417 × 80 lb bags Concrete for a 20×30 ft slab, 6 in thick11.11 yd³500 × 80 lb bags Concrete for a 24×24 ft slab, 4 in thick7.11 yd³320 × 80 lb bags Concrete for a 24×24 ft slab, 5 in thick8.89 yd³400 × 80 lb bags Concrete for a 24×24 ft slab, 6 in thick10.67 yd³480 × 80 lb bags Concrete for a 24×36 ft slab, 4 in thick10.67 yd³480 × 80 lb bags Concrete for a 24×36 ft slab, 5 in thick13.33 yd³600 × 80 lb bags Concrete for a 24×36 ft slab, 6 in thick16 yd³720 × 80 lb bags Concrete for a 30×30 ft slab, 4 in thick11.11 yd³500 × 80 lb bags Concrete for a 30×30 ft slab, 5 in thick13.89 yd³625 × 80 lb bags Concrete for a 30×30 ft slab, 6 in thick16.67 yd³750 × 80 lb bags Concrete for a 30×40 ft slab, 4 in thick14.81 yd³667 × 80 lb bags Concrete for a 30×40 ft slab, 5 in thick18.52 yd³834 × 80 lb bags Concrete for a 30×40 ft slab, 6 in thick22.22 yd³1000 × 80 lb bags Concrete for a 40×60 ft slab, 4 in thick29.63 yd³1334 × 80 lb bags Concrete for a 40×60 ft slab, 5 in thick37.04 yd³1667 × 80 lb bags Concrete for a 40×60 ft slab, 6 in thick44.44 yd³2000 × 80 lb bags

20 guides

Footing

Strip footing runs at the two most common trench sections.

Concrete for a 10 ft footing, 16×8 in0.33 yd³15 × 80 lb bags Concrete for a 10 ft footing, 24×12 in0.74 yd³34 × 80 lb bags Concrete for a 15 ft footing, 16×8 in0.49 yd³23 × 80 lb bags Concrete for a 15 ft footing, 24×12 in1.11 yd³50 × 80 lb bags Concrete for a 20 ft footing, 16×8 in0.66 yd³30 × 80 lb bags Concrete for a 20 ft footing, 24×12 in1.48 yd³67 × 80 lb bags Concrete for a 24 ft footing, 16×8 in0.79 yd³36 × 80 lb bags Concrete for a 24 ft footing, 24×12 in1.78 yd³80 × 80 lb bags Concrete for a 30 ft footing, 16×8 in0.99 yd³45 × 80 lb bags Concrete for a 30 ft footing, 24×12 in2.22 yd³100 × 80 lb bags Concrete for a 40 ft footing, 16×8 in1.32 yd³60 × 80 lb bags Concrete for a 40 ft footing, 24×12 in2.96 yd³134 × 80 lb bags Concrete for a 50 ft footing, 16×8 in1.65 yd³75 × 80 lb bags Concrete for a 50 ft footing, 24×12 in3.7 yd³167 × 80 lb bags Concrete for a 60 ft footing, 16×8 in1.98 yd³89 × 80 lb bags Concrete for a 60 ft footing, 24×12 in4.44 yd³200 × 80 lb bags Concrete for a 80 ft footing, 16×8 in2.63 yd³119 × 80 lb bags Concrete for a 80 ft footing, 24×12 in5.93 yd³267 × 80 lb bags Concrete for a 100 ft footing, 16×8 in3.29 yd³149 × 80 lb bags Concrete for a 100 ft footing, 24×12 in7.41 yd³334 × 80 lb bags

18 guides

Column

Round sonotube piers by diameter and height.

Concrete for a 6 in sonotube, 4 ft tall0.03 yd³2 × 80 lb bags Concrete for a 6 in sonotube, 6 ft tall0.04 yd³2 × 80 lb bags Concrete for a 6 in sonotube, 8 ft tall0.06 yd³3 × 80 lb bags Concrete for a 8 in sonotube, 4 ft tall0.05 yd³3 × 80 lb bags Concrete for a 8 in sonotube, 6 ft tall0.08 yd³4 × 80 lb bags Concrete for a 8 in sonotube, 8 ft tall0.1 yd³5 × 80 lb bags Concrete for a 10 in sonotube, 4 ft tall0.08 yd³4 × 80 lb bags Concrete for a 10 in sonotube, 6 ft tall0.12 yd³6 × 80 lb bags Concrete for a 10 in sonotube, 8 ft tall0.16 yd³8 × 80 lb bags Concrete for a 12 in sonotube, 4 ft tall0.12 yd³6 × 80 lb bags Concrete for a 12 in sonotube, 6 ft tall0.17 yd³8 × 80 lb bags Concrete for a 12 in sonotube, 8 ft tall0.23 yd³11 × 80 lb bags Concrete for a 14 in sonotube, 4 ft tall0.16 yd³8 × 80 lb bags Concrete for a 14 in sonotube, 6 ft tall0.24 yd³11 × 80 lb bags Concrete for a 14 in sonotube, 8 ft tall0.32 yd³15 × 80 lb bags Concrete for a 16 in sonotube, 4 ft tall0.21 yd³10 × 80 lb bags Concrete for a 16 in sonotube, 6 ft tall0.31 yd³14 × 80 lb bags Concrete for a 16 in sonotube, 8 ft tall0.41 yd³19 × 80 lb bags

8 guides

Post holes

Fence and deck post footings, set around a 4×4 post.

Concrete for 6 × 8 in post holes, 24 in deep0.12 yd³6 × 80 lb bags Concrete for 6 × 8 in post holes, 36 in deep0.18 yd³8 × 80 lb bags Concrete for 6 × 10 in post holes, 24 in deep0.2 yd³10 × 80 lb bags Concrete for 8 × 10 in post holes, 30 in deep0.34 yd³16 × 80 lb bags Concrete for 6 × 10 in post holes, 36 in deep0.31 yd³14 × 80 lb bags Concrete for 9 × 12 in post holes, 36 in deep0.7 yd³32 × 80 lb bags Concrete for 9 × 12 in post holes, 42 in deep0.82 yd³37 × 80 lb bags Concrete for 12 × 12 in post holes, 48 in deep1.25 yd³57 × 80 lb bags

10 guides

Steps

Solid poured staircases with code-typical 7 in rises.

Concrete for 2 solid steps, 3 ft wide0.18 yd³9 × 80 lb bags Concrete for 2 solid steps, 4 ft wide0.24 yd³11 × 80 lb bags Concrete for 3 solid steps, 3 ft wide0.36 yd³17 × 80 lb bags Concrete for 3 solid steps, 4 ft wide0.48 yd³22 × 80 lb bags Concrete for 4 solid steps, 3 ft wide0.59 yd³27 × 80 lb bags Concrete for 4 solid steps, 4 ft wide0.79 yd³36 × 80 lb bags Concrete for 5 solid steps, 3 ft wide0.89 yd³41 × 80 lb bags Concrete for 5 solid steps, 4 ft wide1.19 yd³54 × 80 lb bags Concrete for 6 solid steps, 3 ft wide1.25 yd³57 × 80 lb bags Concrete for 6 solid steps, 4 ft wide1.66 yd³75 × 80 lb bags

6 guides

Curb

Plain curb and curb-and-gutter runs.

Concrete for a 20 ft curb0.56 yd³25 × 80 lb bags Concrete for a 20 ft curb and gutter0.8 yd³37 × 80 lb bags Concrete for a 50 ft curb1.39 yd³63 × 80 lb bags Concrete for a 50 ft curb and gutter2.01 yd³91 × 80 lb bags Concrete for a 100 ft curb2.78 yd³125 × 80 lb bags Concrete for a 100 ft curb and gutter4.01 yd³181 × 80 lb bags

8 guides

Mortar

Which ASTM C270 mortar type each kind of masonry wants.

Mortar mix ratio for brickMix ratio Mortar mix ratio for concrete blockMix ratio Mortar mix ratio for stoneMix ratio Mortar mix ratio for a retaining wallMix ratio Mortar mix ratio for a chimneyMix ratio Mortar mix ratio for repointingMix ratio Mortar mix ratio for pavingMix ratio Mortar mix ratio for foundation masonryMix ratio

9 guides

Concrete mix

The nominal mix to use for each kind of pour.

Concrete mix for a drivewayMix ratio Concrete mix for a patioMix ratio Concrete mix for a footingMix ratio Concrete mix for a fence postMix ratio Concrete mix for a shed baseMix ratio Concrete mix for a garage floorMix ratio Concrete mix for a foundationMix ratio Concrete mix for a slabMix ratio Concrete mix for stepsMix ratio

3 guides

Render

Render and stucco coats, from scratch coat to finish.

Render mix ratio for an exterior wallMix ratio Stucco mix ratio for the scratch coatMix ratio Render mix ratio for the finish coatMix ratio

2 guides

Screed

Floor screed mixes, bonded and floating.

Screed mix ratio for a floorMix ratio Screed mix ratio over underfloor heatingMix ratio

2 guides

Grout

Masonry grouts for block cores and bond beams.

Grout mix ratio for block coresMix ratio Grout mix ratio for a bond beamMix ratio