How to Calculate Steel Billet Weight (Formula and Examples)
Formulae for the weight of square and round steel billets and blooms, with worked examples.
The formulae
The density of steel is about 7.85 g/cm³. For a square section, weight in kg per metre is side in mm, squared, × 0.00785. For a round section it is diameter in mm, squared, × 0.006165.
Worked examples
A 100 × 100 mm square: 100 × 100 × 0.00785 = 78.5 kg per metre in theory. A 160 × 160 mm square: 160 × 160 × 0.00785 = 201 kg per metre. A 200 mm round: 200 × 200 × 0.006165 = 246.6 kg per metre.
Why catalogue weights differ
Real billets have rounded corners and dimensional tolerance, so actual weight per metre is slightly lower than theory. Kesari Alloys' indicative weights are within ±3%.
Use the calculator
The billet weight calculator on this site gives weight per metre and total weight for any size and length.
Related guides
What Is a Steel Billet? Sizes, Grades and Uses
A plain guide to steel billets: how they are made, typical sizes, grades and where they are used.
How to Choose the Right Billet Size for Forging and Rolling
A method to match billet or bloom section to the finished forging or rolled section, using reduction ratio and yield.
Reduction Ratio: Why It Matters When Rolling or Forging Billets
How the reduction ratio between billet and finished section affects soundness, grain and ultrasonic test results.
Billet size chart · Weight calculator · Steel grade directory