What does this tool do?
A concrete mix is specified as cement, sand and gravel parts by volume. This calculator separates the cement share of the total volume, converts it to bags and reports the sand and gravel quantities for the same mix.
The Formula
Cement volume = Total volume × Cement parts ÷ Total parts; Bags = ⌈Cement volume ÷ Bag yield⌉Frequently Asked Questions
How many bags of cement for one cubic yard?
A 1:2:3 mix at 27 cu ft needs about five 94 lb bags of cement, plus sand and gravel.
Should I use bags or ready-mix?
Bags suit small jobs up to about half a cubic yard; ready-mix is faster and more consistent above that.