Calculator
Project management cost calculator — Malaysia
Three figures per line item instead of one. You get the PERT expected cost, a confidence range, and a budget with contingency on top.
| Line item | Optimistic | Most likely | Pessimistic | Expected | ± 1σ |
|---|---|---|---|---|---|
| 155,000 | 15,000 | ||||
| 116,667 | 16,667 | ||||
| 41,667 | 11,667 | ||||
| 20,833 | 2,500 |
Expected cost
RM334,167
68% confidence: RM308,767 – RM359,566
95% confidence: RM283,367 – RM384,966
Budget with 10% contingency
RM367,583
Contingency RM33,417 on top of the expected cost.
Line deviations are combined in quadrature — √(Σσ²) = RM25,400, not the straight sum of RM45,833. Adding them assumes every line goes wrong at once in the same direction, which overstates the range and makes an otherwise sound estimate easy to dismiss.
Why three numbers beat one
A single-point estimate hides everything useful. RM150,000 could mean "I am confident within a few thousand" or "somewhere between eighty and three hundred", and the budget holder cannot tell which.
The three-point method asks for the optimistic, most likely and pessimistic cases, then weights them: expected cost is (O + 4M + P) divided by six. The most likely case carries four times the weight, so the answer stays anchored to realism while acknowledging the tails.
The spread also gives you a standard deviation, (P − O) divided by six, which is what turns an estimate into a range with a stated confidence rather than a number with an implied one.
⚠️ Across line items, deviations combine in QUADRATURE — the square root of the sum of squares — not by simple addition. Adding them assumes every line goes wrong at once in the same direction. That overstates the range, and an overstated range is the fastest way to have a sound estimate dismissed.
Contingency, and how to make it survive a budget meeting
Contingency defended as a number is usually cut; contingency defended as a probability usually is not. "Ten per cent because we always add ten per cent" invites a negotiation. "This figure takes us from roughly even odds to about 95% confidence" is a different conversation, because cutting it becomes an explicit decision to accept risk.
Keep contingency visible and separate rather than padding individual lines. Hidden padding gets spent quietly and early, and nobody can tell afterwards whether the estimate was wrong or the buffer was consumed.
Decide who releases it and on what basis before the project starts. Contingency with no release rule is treated as budget by everyone who can see it.
And separate contingency from management reserve. One covers the risks you identified; the other covers the ones you did not, and they are not interchangeable.
Questions
›What is the PERT formula?
Expected value equals optimistic plus four times most likely plus pessimistic, all divided by six. The standard deviation is pessimistic minus optimistic, divided by six.
The weighting keeps the estimate anchored to the realistic case while still letting the extremes influence it.
›Why not just add up the best guesses?
Because a single number carries no information about how uncertain it is, and every estimate in a project has a different amount of uncertainty.
The line with a RM10,000 spread and the line with a RM160,000 spread need very different treatment, and a single-point estimate makes them look the same.
›How much contingency should I add?
Rather than picking a percentage, use the confidence range. Expected cost plus one standard deviation is roughly 84% confidence; plus two is roughly 95%.
Then state which you chose and why, so that reducing it is a visible decision about risk appetite rather than a quiet trim.
›Does this handle currencies other than ringgit?
The arithmetic is currency-agnostic — only the labels say RM. Keep every line in one currency.
If your project spans currencies, convert first and treat the exchange rate as its own risk, because it is one.
Get a scoped quote
Tell us your team size, timeframe and whether you pay the HRD Corp levy. Within one working day you get a day rate, a suggested course shape and how to claim it through HRD Corp.