FREE · CALCULATORS & CONVERTERS
Rebar Calculator.
Count reinforcing bars from spacing and cover, then estimate length, lap and steel mass.
Metric mass uses d²/162 kg/m. US mass uses nominal pounds per foot for sizes #3 to #18. Lap is a multiple of the nominal diameter. Local arithmetic only. This is a quantity or geometry estimate, not a code check and not a substitute for a licensed professional.
- Bars per layer
- 40
- Bars
- 40
- Lap length
- 0.48 m
- Total length
- 240 m
- Mass
- 213.333333 kg
- Mass
- 470.319493 lb
Bar count is floor((run − 2 × cover) / spacing) + 1. Metric mass uses d²/162 kilograms per metre, with d in millimetres. Lap length is the multiple times the nominal diameter.
How to use Rebar Calculator
Choose metric or US bars, enter the run, spacing, cover and cut length. Review the bar count and mass.
How it works
Count reinforcing bars from spacing and cover, then estimate length, lap and steel mass. Metric mass uses d²/162 kg/m. US mass uses nominal pounds per foot for sizes #3 to #18. Lap is a multiple of the nominal diameter. Local arithmetic only. This is a quantity or geometry estimate, not a code check and not a substitute for a licensed professional.
Example
12 mm bars at 150 mm centres over a 6 m run.
Questions about Rebar Calculator
Is Rebar Calculator free, and do I need an account?
Yes. This tool is free to use in your browser without an account. Processing takes place on your device.
What are the limits and what should I check?
Metric mass uses d²/162 kg/m. US mass uses nominal pounds per foot for sizes #3 to #18. Lap is a multiple of the nominal diameter. Local arithmetic only. This is a quantity or geometry estimate, not a code check and not a substitute for a licensed professional. Review the result before using it in your work.
Is my input sent to a server?
Your input is processed in your browser and is not uploaded by this tool. Files and pasted text are cleared when the page is refreshed. Normal website requests are still required to load the page and its libraries. Read the privacy explanation.