Yard Materials Calculator
How much mulch, topsoil, gravel or concrete you need, in cubic yards, cubic feet and bags. Includes fence post holes. No prices, just quantities.
Quantities only, no prices. Bag counts are rounded up to whole bags.
| Step | Result |
|---|---|
| Enter your measurements to see how much you need. | |
Bags needed
Planning a fence? Post-hole concrete isn't priced in our Fence Cost Calculator. Contractor quotes usually say whether post setting is included; the Fence Quote Checker asks about it.
What the labels mean
- Sourced published by a cited source, used as published
- Our calculation math on sourced numbers (averages, midpoints, totals)
- Assumption our own choice where no source covers it
Bag yields are Sourced. Every area, volume and bag count is Our calculation.
How we calculate
- Our calculation Area: rectangle = length × width; circle = π × (diameter ÷ 2)², in square feet.
- Our calculation Volume: cubic feet = area × depth in inches ÷ 12. Cubic yards = cubic feet ÷ 27.
- Our calculation Waste: if you enter a percentage, we multiply the volume by (1 + waste ÷ 100) once.
- Our calculation Post holes: each hole is a cylinder, π × (hole diameter ÷ 2)² × depth, minus the post: width² for a square post or π × (diameter ÷ 2)² for a round one, over the depth the post sits in concrete (hole depth − concrete under the post). Cubic inches ÷ 1,728 = cubic feet, times the number of holes.
- Our calculation Bags: volume ÷ the bag's volume or yield, rounded up to a whole bag.
- Assumption The hole is filled to the top with concrete and the sides are straight. Real holes are rarely perfect cylinders.
- Assumption Loose materials aren't compacted. Mulch, topsoil and gravel settle; add a waste percentage if you want extra.
Concrete bag yields we use
Each yield is the figure printed on the manufacturer's data sheet, checked October 13, 2026.
| Product | Bag | Yield | Label |
|---|---|---|---|
| QUIKRETE Concrete Mix (No. 1101) | 80 lb | 0.6 ft³ | Sourced data sheet |
| QUIKRETE Concrete Mix (No. 1101) | 60 lb | 0.45 ft³ | Sourced data sheet |
| QUIKRETE Concrete Mix (No. 1101) | 50 lb | 0.375 ft³ | Sourced data sheet |
| QUIKRETE Concrete Mix (No. 1101) | 40 lb | 0.3 ft³ | Sourced data sheet |
| QUIKRETE Concrete Mix (No. 1101) | 90 lb | 0.675 ft³ | Sourced data sheet |
| QUIKRETE Fast-Setting Concrete Mix (No. 1004) | 50 lb | 0.375 ft³ | Sourced data sheet |
| QUIKRETE Fast-Setting Concrete Mix (No. 1004) | 60 lb | 0.45 ft³ | Sourced data sheet |
Sources: QUIKRETE Concrete Mix (No. 1101) data sheet (revised November 2025) and QUIKRETE Fast-Setting Concrete Mix (No. 1004) data sheet.
A check against the manufacturer: the Fast-Setting data sheet says two 50 lb bags set a 3-in square post in a 9-in hole 30 in deep. Filled to the top, that hole holds about 0.95 ft³ (our calculation), about 2.5 bags at 0.375 ft³ each, so this calculator says 3 bags. Buy for the volume you'll actually fill, and keep a spare bag if you're unsure.
What this calculator doesn't do
- No prices. Material prices vary by store and region, and we don't have reliable data for them.
- No hole sizes or footing depths. Those depend on your post, soil, frost line and local code. QUIKRETE's data sheet says to follow local building codes for load-bearing footings.
- No weight-based conversions (tons of gravel). Density varies by product, and we don't have a sourced figure.
Pricing a fence? Use the Fence Cost Calculator and the Fence Quote Checker.