What an 8x10 slab is for
An 8x10 slab is the base for one of the most common small storage sheds, sold as an 8x10 kit. It also makes a pad for a small hot tub, a spot for a grill and two chairs, or a landing at the foot of a set of steps.
Concrete for an 8x10 slab at 4, 5 and 6 inches
Every inch of thickness on an 8x10 slab is 6.7 cubic feet, or 0.25 cubic yards. The ready mix order and the bags in this table include 10 percent extra. Change the thickness or the extra in the calculator above.
| Thickness | Cubic feet | Cubic yards | Ready mix to order | 80 lb bags | 60 lb bags |
|---|---|---|---|---|---|
| 4 in | 26.7 | 0.99 | 1.09 cu yd | 49 | 66 |
| 5 in | 33.3 | 1.23 | 1.36 cu yd | 62 | 82 |
| 6 in | 40 | 1.48 | 1.63 cu yd | 74 | 98 |
The 4 inch row by hand: 10 × 8 × 0.333 = 26.7 cubic feet, and 26.7 ÷ 27 = 0.99 cubic yards. With 10 percent extra that is 29.3 cubic feet. An 80 lb bag makes 0.60 cubic feet and a 60 lb bag makes 0.45, so it takes 49 of one or 66 of the other.
Quikrete says a sidewalk should be at least 4 inches thick and small slabs normally run 4 to 6 inches, depending on the load. The concrete slab calculator page covers what the building code asks for.
Bags or a truck for an 8x10 slab
From bags, it is 49 bags of 80 lb mix at 4 inches, 3,920 lb to lift and mix, about $279 at McCoy's price of $5.99 a bag, or $5.69 for 42 or more.
From a truck, it is 1.09 cubic yards, about $120 to $164 at HomeAdvisor's $110 to $150 per cubic yard delivered. The National Ready Mixed Concrete Association says a truck mixer carries 8 to 12 cubic yards, so this is less than one truck load. HomeAdvisor says an order under a full truckload can carry a short-load fee of $40 to $60 per cubic yard, and suppliers often have a minimum order.
By these prices an 8x10 slab costs about $115 to $159 less from a truck than from bags, and it saves lifting 3,920 lb of mix. A short-load fee or a minimum order comes out of that gap, so get a delivered price for 1.09 cubic yards and compare it with $279. It is a bag job only if that quote comes in higher or a truck cannot reach the slab. The association notes that a loaded truck weighs about 80,000 lb and may not be able to cross loose dirt or a residential curb.
| Thickness | 80 lb bags | Bags weigh | Bags cost | Ready mix | Ready mix cost |
|---|---|---|---|---|---|
| 4 in | 49 | 3,920 lb | $279 | 1.09 cu yd, less than one truck load | $120 to $164 |
| 5 in | 62 | 4,960 lb | $353 | 1.36 cu yd, less than one truck load | $150 to $204 |
| 6 in | 74 | 5,920 lb | $421 | 1.63 cu yd, less than one truck load | $179 to $244 |
Prices are from the sources below, checked in October 2026; multiply the table by your own to compare. Gravel, steel, forms, finishing and labor are extra.
Pouring an 8x10 slab
An 8 foot width is easy to work. A 10 foot 2x4 laid across the forms reaches both sides, so two people can screed it in one pass, and you can reach the middle from the edge with a hand float on a short handle. At about one cubic yard, it is the smallest pour on this list, and a ready mix plant may have a minimum order bigger than that. Bags in a wheelbarrow or a small mixer are often how a slab this size gets done.
Gravel base and slope
A 4 inch gravel base under an 8x10 slab is 26.7 cubic feet, or 0.99 cubic yards. Quikrete says to spread and compact 3 to 4 inches, and a 3 inch base is 20 cubic feet, or 0.74 cubic yards. Those are volumes of the finished layer. Gravel settles when it is compacted, so order a little more.
Outside, Quikrete says to slope the slab away from buildings and gives 1/4 inch per foot as the usual fall. Running across the 8 foot side, that is 2 inches from one edge to the other. Running along the 10 foot side, it is 2 1/2 inches. Set the forms to the slope, and the screed follows them.
Rebar or wire mesh
With bars 24 inches on center both ways, held 3 inches back from each edge, an 8x10 slab takes 5 bars 9 feet 6 inches long and 6 bars 7 feet 6 inches long. That is 93 feet of bar. With 10 percent extra, buy 6 bars 20 feet long. Every bar is shorter than the 20 foot length sold, so none has to be joined.
With wire mesh instead, one sheet 8 feet by 12.5 feet, lapped 8 inches, covers it. The spacing and the sheet size are where the calculator starts. Your plans or your building department set the steel for your slab.
Control joints
Quikrete says control joints in a 4 inch slab go every 6 to 8 feet and about a quarter of the slab deep, which is 1 inch. Keeping them no more than 8 feet apart cuts an 8x10 slab into 2 panels along the 10 foot side and leaves the 8 foot side whole. That makes 2 panels, each 5 feet by 8 feet, with 8 feet of joint to cut.
Before you pour an 8x10 slab
Pour a shed pad to the outside size of the shed walls, not bigger. A lip of concrete outside the walls catches rain running off the siding and sends it under the sill. For a hot tub, read the maker's install guide before you pour: a filled tub with people in it can weigh well over two tons, and the guide sets the slab it needs.
Other slab sizes
8x1010x1010x1212x1210x2012x2016x2020x2020x2424x2424x3030x40
Common questions
How much concrete do I need for an 8x10 slab?
An 8 by 10 foot slab 4 inches thick holds 26.7 cubic feet of concrete, which is 0.99 cubic yards. With 10 percent extra, order 1.09 cubic yards of ready mix. At 5 inches thick it holds 1.23 cubic yards and at 6 inches 1.48.
How many 80 lb bags of concrete do I need for an 8x10 slab?
49 bags at 4 inches thick, with 10 percent extra. They weigh 3,920 lb in all and cost about $279 at the store price checked in October 2026. At 5 inches thick it is 62 bags and at 6 inches 74.
How thick should an 8x10 concrete slab be?
Quikrete calls for at least 4 inches for a sidewalk and 4 to 6 inches for small slabs, depending on the load. The International Residential Code minimum for a house floor slab is 3.5 inches. On an 8x10 slab each extra inch adds 0.25 cubic yards, so going from 4 to 6 inches takes the ready mix order from 1.09 to 1.63 cubic yards. Ask your building department what it wants for a driveway or a garage floor.
Is an 8x10 slab big enough for a hot tub?
For a small one, yes. Many hot tubs are about 7 feet square, which leaves a foot to spare across the 8 foot side and 3 feet along the 10 foot side, room for the steps. The maker's install guide sets the thickness and the steel, so read it before you pour.
Do I need a permit for an 8x10 shed on a slab?
Often not. The model code (IRC R105.2) lets a one-story detached shed of up to 200 square feet go without a building permit, and 8x10 is 80. Your town can set its own limit, and zoning rules on how close to the property line you build still apply.
Tools for this job
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- Form stakes. Hold the form boards in place while you pour.
- Concrete float. Smooths the surface after the concrete is leveled.
- Edger. Rounds the slab edges so they do not chip.
- Groover. Cuts control joints so cracks follow a straight line.
- Finishing trowel. Gives the slab its final smooth surface.
- Rubber boots. Keep wet concrete off your skin while you stand in the pour.
Sources
- Quikrete, Pouring and Finishing Concrete Slabs
- Quikrete, Concrete Sidewalks and Small Slabs project guide
- Quikrete Concrete Mix data sheet (yield per bag)
- National Ready Mixed Concrete Association, CIP 31: Ordering Ready Mixed Concrete
- International Residential Code 2021, Chapter 5: concrete floors on the ground (R506)
- International Residential Code 2021, Chapter 4: foundations (R403, concrete cover over steel)
- Wire Reinforcement Institute, Manual of Standard Practice: Structural Welded Wire Reinforcement
- City of Dubuque, Iowa, minimum requirements for a detached garage slab
- City of Fridley, Minnesota, Garage Slabs handout
- PJ's Rebar, stock rebar sizes and lengths
- International Residential Code 2021, Chapter 1: work exempt from permit (R105.2)
- McCoy's Building Supply: Quikrete Concrete Mix, 80 lb bag
- HomeAdvisor: concrete delivery cost, per cubic yard and short-load fees
Facts on this page were last checked against these sources in October 2026.