Use these free concrete calculators to estimate how much concrete you'll need for slabs, footings or columns. It is a good idea to overestimate the amount of concrete needed so you won't come up short on the jobsite. Show
CONCRETE CALCULATOR FORMULAWhat equation should I use to find out how much concrete I need?How to calculate concrete:
Here’s what the math looks like for a 10’ by 10’ concrete patio:
Essentially you are solving for volume and then converting to cubic yards. For concrete, the formula for volume is as follows: length x width x thickness. To determine how many bags of concrete you will need, divide the total cubic yards needed by the yield. Use the following yields per each bag size:
READY MIX VS. BAGGED CONCRETEShould I order concrete by the yard from a ready mix company or just use bags?Larger jobs such as driveways are easier to complete when ordering concrete by the yard, rather than trying to mix bag after bag by hand. For smaller jobs, like a walkway, modest patio or footings, you should calculate the number of concrete bags instead. Bagged concrete is ideal for:
If you’re purchasing bagged concrete you may be able to have it delivered, but if it is only a few bags you’ll be responsible for transporting it yourself. You’ll also need additional equipment for mixing the concrete. A rented mixer can be very helpful, but a wheelbarrow works for just a few bags. Ready mixed concrete by the yard is good for:
If you’re planning to order concrete from a ready mix supplier, they’ll need to know how many yards of concrete to deliver. Many ready mix companies will have a minimum order of 1 yard, and will charge shortage fees when ordering partial batches. The average truck holds between 9 and 11 yards total. If your project requires more concrete, multiple trucks will be necessary. How much does concrete weigh?Concrete is usually ordered in cubic yards, but if you're looking for concrete weight it varies depending on the type of mix being used. However, most ready mix suppliers estimate that a cubic yard of concrete weighs about 4,000 lbs. So if you need three yards, that would be around 12,000 lbs (3yds x 4,000lbs). Ask your supplier if you'd like to know the exact weight. CONCRETE ESTIMATING TIPS
Calculating the amount of concrete needed for slabs (including odd shapes)Rule of thumb: add 1/4" to the thickness of your slab for your slab concrete budget. This assumes you have the job evenly graded to the right depth, and the grade is well compacted. If you check your grade and one spot is 4", some spots are 4.5" to 5"-the best solution for both the job quality and your concrete budget is to fix the grade. Odd shapes: Transform odd shapes into rectangles and odd shapes are suddenly easy to figure. Figure driveway 14' x 20' and your estimate will be good. Here is why: The driveway is 16' at the top and 12' at the bottom. Through the center the width averages 14'. Calculating the amount of concrete needed for footingsFootings will rarely follow the drawing exactly. In rocky soil the footings may collapse when big rocks are excavated This was supposed to be a 12"*12" footing, but note how the left side of the footing has collapsed. Calculate the true width. The excavator may have dug too deep, or it may have rained and footings needed to be dug out deeper to reach firm soil. So it is important to check a variety of spots on your footing and get an average size. Then use the calculator to figure the amount of concrete needed. House slabs on grade that are 8" out of grade with a 4" slab also have some of the footing above the grade too. This 12" x 12" footing needs to be calculated 12" x 16" so the footing is figured to go above grade to reach the 4" slab thickness.
Estimating concrete stepsSteps seem tricky to calculate but are not. If there are three steps leading up to a porch:
Here is an example: This porch has 9 sq. feet of porch surface, so enter in the slab calculator 4" thickness by 3' width by 3' length. This totals .11 cubic yards. The porch also has 9 linear feet of 6" step. So enter in the footing calculator, 6" depth by 12" width (always figure steps with a 12" width) by 9' length. This totals .17 cubic yards. The total concrete needed for the 3' by 3' porch will be .28 cubic yards. (.11 + .17 cubic yards = .28 cubic yards) Repeat this for added layers of steps.
3' x 3' Porch Calculating the amount of base fillUsing a Margin of Safety: Problems Caused by Underestimating the Amount of Concrete Never try to order the exact amount of needed concrete. Include a margin of safety. A perfectly placed order of concrete will finish the job with a small amount left over. A 20 cubic yard order with 1 cubic yard left over is a good order. A 20 cubic yard order that comes up cubic yard short is not a good order. Extra costs of coming up short of concrete
Three steps to ordering enough concrete:
Rule of thumb for margin of safety:
It can be upsetting to end up with any extra concrete. You are having to pay for this concrete after all. However, realize you are doing your job a service by ordering enough concrete - which means you are going to have a little concrete left. Requesting your ready mix supplier to visit your siteAfter you have chosen a Ready Mix Supplier, have a representative come to your site to give his/her opinion on the quantity required. Compare the figure with what you came up with. Discuss any variances with the supplier. Your ready mix supplier is invaluable for checking your view of job conditions, checking your margin of safety, identifying issues you may not have thought of, and informing you of any local conditions you need to be aware of. Last updated: September 7, 2022 How many 80lb bags of concrete does it take to make a yard?How many concrete bags do you need? One 80lbs bag of Quikrete Concrete Mix will yield approximately . 60 cu ft. So it will take 45 bag to equal one cubic yard of concrete.
How many bags of concrete is 3 yards?As per general rules and guidelines, for making 3 yards, generally you will need 135 bags of 80 lb concrete or 180 bags of 60 lb or 270 bags of 40 lb concrete. As 3 yards = 81 cubic feet, number of bags calculated by dividing 3 yards or 81 cu ft by one bag yields, so 1) No. of 80 lb bags = 81 ÷ 0.60 = 135 bags, 2) No.
How many 80lb bags of concrete does it take to make 2 yards?To create a yard with 50lb bags of concrete, you'll need 72 bags. To create a yard with 60lb bags of concrete, you'll need 60 bags. To create a yard using 80lb bags of concrete, you'll need 45 bags. You can use this concrete calculator to compute the quantity of bags of concrete.
How far will a 80lb bag of concrete go?A 80 pound bag of concrete would cover 2 square feet. A 90 pound bag of concrete would cover little more than 2 square feet. A 60 pound bag of concrete would cover 1.5 square feet.
|
How many 80lb bags of concrete do I need for 3 yards?
Copyright © 2024 ShotOnMac Inc.
