---
title: "Concrete Calculator — Cubic Yards, Cubic Metres & Bags (US, UK, AU)"
description: "Calculate how much concrete you need for a slab, footing, or column. Shows cubic yards (US), cubic metres (UK/AU), and bag counts for 60 lb, 80 lb, 20 kg, and 25 kg bags."
url: "https://worldcalculators.org/calculators/concrete/"
canonical: "https://worldcalculators.org/calculators/concrete/"
---

# Concrete Calculator

Calculate how much concrete you need for a slab, footing, or column. Shows cubic yards (US), cubic metres (UK/AU), and bag counts for 60 lb, 80 lb, 20 kg, and 25 kg bags.

## Quick answer

The concrete you order differs by country — not just in units, but in how strength is specified.

## Concrete Mix Standards by Country

The concrete you order differs by country — not just in units, but in how strength is specified.

## Frequently Asked Questions

A 60 lb (27 kg) bag yields approximately 0.45 ft³ (0.013 m³). For a 4-inch slab, that covers about 1.35 ft². An 80 lb bag covers ~1.8 ft² at 4 inches. For large pours (over 1 cubic yard), ordering ready-mix concrete is usually more economical than bags.
Standard ratios (cement:sand:aggregate): General purpose 1:2:4, Footings/foundations 1:3:6, Structural/reinforced 1:1.5:3. Bagged premixes like Quikrete (US) and Postcrete (UK) are pre-blended — just add water. In Australia, specify concrete by N-class (N20, N25, N32) from a ready-mix supplier.

Source: https://worldcalculators.org/calculators/concrete/
Markdown mirror of the HTML page. Prefer this URL for RAG; the interactive calculator still lives on the HTML page.