How the PERT Estimate works
Expected = (O + 4M + P) ÷ 6; σ = (P − O) ÷ 6.
How to use this calculator
- Sign up free and verify your email to unlock the calculator.
- Choose Metric (m, mm, m³, kg) or Imperial (ft, in, cft, lb) units.
- Enter the optimistic, most likely, pessimistic.
- Results update instantly — read the quantities in the Results panel.
- Add a wastage allowance and confirm against your drawings and specifications before ordering.
Typical uses
Three-point estimating for uncertain activities.
Assumptions & limitations
Results are planning estimates based on standard assumptions for project management work. They do not replace structural design, site measurement or project specifications. Material densities, wastage and mix proportions vary by region and supplier.
Frequently asked questions
- How does the PERT Estimate work?
- Expected = (O + 4M + P) ÷ 6; σ = (P − O) ÷ 6.
- Can I use the PERT Estimate in feet and inches?
- Yes. Switch to Imperial and enter feet, inches, square feet or pounds — the calculator converts automatically and shows results in imperial units.
- When should I use the PERT Estimate?
- Three-point estimating for uncertain activities.
- Is this construction calculator free?
- Yes. All CM PRO construction calculators are free — you only need to sign up and verify your email.
Related searches: PERT calculator, three point estimate, PERT formula.
