Sonotube Calculator

Sonotube Calculator works out how much concrete you need to fill cylindrical tube forms — the cardboard or fibre tubes used for deck piers, fence posts, footings and round columns. Enter the tube size, how many you are pouring and a little wastage, and it shows the volume, bag count and weight in seconds. It works completely offline and nothing you enter ever leaves your phone.

HOW IT WORKS
A tube form is a cylinder, so the concrete it holds is:

volume = π × (diameter / 2)² × height

The app multiplies that by the number of tubes and adds your wastage allowance, then converts the result into cubic metres, cubic feet and cubic yards. For example, a 12-inch tube 4 feet tall holds about 3.14 cubic feet.

WHAT YOU CAN DO
• Enter diameter, height, quantity and wastage and read the total concrete instantly
• Work in metric (centimetres and metres) or imperial (inches and feet) — switch any time
• See the volume in cubic metres, cubic feet and cubic yards at once
• Get the number of bags for 20 kg, 40 lb, 60 lb and 80 lb premix presets, rounded up
• Estimate the approximate weight of the pour in kilograms and pounds
• Open the Details tab for a full breakdown, per tube and total
• Learn the formula, bag yields and why wastage matters with a plain-language guide

BUILT FOR THE JOB SITE
A clean, sturdy design puts the big number first, with supporting figures right beside it. Light and dark themes, a tiny download, no clutter and no account required.

AN ESTIMATE, NOT AN ENGINEERED QUANTITY
This is a simplified educational tool for planning. Real pours vary with the actual form size, spillage, over-excavation, sub-grade and your specific concrete mix and density. Bag yields differ by brand. Always confirm quantities with your supplier and follow the form and mix manufacturer's instructions. This app is for general information only and is not engineering, construction or professional advice. Sonotube is a trademark of its respective owner and is used here only to describe the type of tube form; this app is not affiliated with or endorsed by that owner.

PRIVACY
The app collects no personal data and works fully offline. Ads are served by Google AdMob, which may use an advertising identifier as described in Google's policies.

Download Sonotube Calculator and get a fast, sensible estimate of the concrete, bags and weight for your next set of footings or columns.