How to use the Test Estimation Calculator
- 1. Pick a methodUse test case based if you know the count, or PERT for early estimates.
- 2. Enter your numbersAdd per-case timings and percentages, or optimistic, likely and pessimistic values.
- 3. PlanRead total hours, person-days and calendar days for your team size.
Test case based estimate
When you know roughly how many test cases you need, add up the work: design + execution + re-test + overhead. Re-test is a share of execution time for verifying fixes and regression; overhead covers meetings, reporting and environment setup.
Worked example (defaults): 120 test cases at 20 minutes design is 40 hours, 15 minutes execution is 30 hours, 25% re-test adds 7.5 hours, so the subtotal is 77.5 hours. 15% overhead adds 11.63 hours, for 89.13 hours in total. At 8 hours a day that is 11.14 person-days, or about 5.6 working days for two testers.
Three-point (PERT) estimate
Early in a project you may only have a feel for the size. Ask for three numbers: optimistic (O), most likely (M) and pessimistic (P). PERT gives the expected value E = (O + 4M + P) ÷ 6 and a spread SD = (P − O) ÷ 6. For O = 10, M = 16 and P = 28 days, E = 17 days with SD = 3, so a 95% planning range is roughly 11 to 23 days.
- Use your own team's past numbers for minutes per case; they vary widely.
- Add a buffer for unstable builds and environment downtime.
- Re-estimate when scope changes instead of squeezing the same dates.
An estimate is a forecast, not a promise. Put it into the schedule section of the test plan generator, and cut the number of cases with the pairwise generator.
Frequently asked questions
Which method is more accurate?
Test case based is better once requirements are known. PERT is better very early, when you only have ranges.
Do calendar days include weekends?
No. They are working days based on the hours per day and number of testers you enter.
Is the Test Estimation Calculator free?
Yes, the Test Estimation Calculator is free. The first time you see your first estimate, you are asked for your name and WhatsApp number once. After that, this and every other Uncodemy tool opens straight away without the form.