Sonotube Concrete Calculator
Sonotube concrete calculator for piers, posts, and round footings.
Estimate concrete for sonotube forms, round piers, deck footings, fence post holes, pole barn post footings, and cylindrical concrete columns. Use the main concrete calculator to enter diameter, depth, quantity, waste, and concrete price.
How to calculate concrete for a sonotube
A sonotube or round pier is calculated like a cylinder. Convert the tube diameter into a radius, square the radius, multiply by pi, then multiply by depth and quantity.
Formula
π × Radius² × Depth × Quantity = Concrete Volume
For imperial estimates, diameter is commonly entered in inches and depth in feet. The calculator converts the result into cubic feet and cubic yards. For metric estimates, diameter is entered in centimeters and depth in meters.
Sonotube concrete example
Four round piers with a 12 inch diameter and 3 ft depth require about 9.42 cubic feet of concrete. Since one cubic yard equals 27 cubic feet, that is about 0.35 cubic yards before waste. With 10% waste, the estimate is about 0.38 cubic yards.
Bags vs Truck Delivery
Should you use concrete bags or ready-mix for sonotubes?
Sonotubes, fence post holes, deck footings, pergola footings, and small round piers are often good candidates for bagged concrete. Larger pier layouts, pole barn footings, and projects with many tubes may become faster and more practical with ready-mix truck delivery.
Bagged concrete
Best for post holes, deck piers, mailbox posts, small pergola footings, and low-volume tube forms. The main concrete calculator estimates 80 lb bags, 60 lb bags, pallets, and bag cost.
One-pallet rule
One common pickup-load pallet is about 42 bags of 80 lb concrete or 56 bags of 60 lb concrete. If your sonotube project exceeds one pallet, compare the bag cost against truck delivery.
Ready-mix truck
Ready-mix may be better for many piers, deep tubes, pole barn posts, and structural round footings. A standard concrete truck is commonly limited to about 10 cubic yards per legal load.
Related sonotube tools
Use these related calculators to estimate project area, concrete volume, round piers, footing trenches, slab quantities, gravel base, and overall construction material needs.
Area Calculator
Calculate square feet, square yards, square meters, acres, waste-adjusted area, and material cost before estimating post, deck, or pier layouts.
Concrete Calculator
Estimate concrete volume, waste, and material cost for slabs, footings, piers, walls, stairs, curbs, and columns.
Concrete Cost Calculator
Estimate sonotube concrete price, rebar, labor, prep, delivery fees, and total project cost.
Concrete Footing Calculator
Estimate concrete for strip footings, trench footings, wall footings, and grade beams.
Rebar Calculator
Estimate rebar length, weight, waste, and cost for piers, posts, sonotubes, and concrete reinforcement.
Concrete Mix Ratio Calculator
Estimate cement, sand, gravel, water, cement bags, and material quantities for common concrete mix ratios.
Concrete Bag Calculator
Estimate how many bags of concrete are needed for post holes, sonotubes, small piers, and deck footings.
Concrete Slab Calculator
Estimate concrete needed for patios, pads, driveways, garage floors, and slab projects.
Gravel Calculator
Estimate gravel, crushed stone, road base, cubic yards, tons, waste, and cost for base preparation.
Construction Calculators
Browse concrete, gravel, base, area, and construction estimating calculators.
Sonotube calculator FAQ
What measurements do I need for a sonotube estimate?
You need the tube diameter, depth or height, quantity of tubes, waste percentage, and concrete price.
Is a sonotube calculated as a cylinder?
Yes. A sonotube is a cylindrical form, so the volume formula uses pi times radius squared times depth.
Can this be used for fence post holes?
Yes. Use the Round Pier / Sonotube mode in the main concrete calculator and enter the hole diameter, depth, and quantity.
Does this include the post volume?
No. This estimate assumes the hole or tube is filled with concrete. If a post displaces concrete volume, the actual amount may be slightly lower.