Monte Carlo project budget calculator

Calculate simulated mean total cost and empirical median cost with your own figures.

Your numbers

Use the units shown. Results update as you change valid inputs.

Choose the currency for these amounts. Changing it keeps your numbers and does not convert exchange rates.

Use simulated mean total cost and empirical median cost to compare changes to your inputs. The method and limits below explain the scope.

Examples

Examples

Try the starting example

Items: name, minimum $, mode $, maximum $, quantile group or independent
Design,100,150,200,independent Build,300,400,500,independent
Simulation trials: 20–10000
2000
Unsigned 32-bit seed
42
Budget threshold ($)
600
Simulated mean total cost ($)
$551.00
Empirical median cost ($)
$550.99
Empirical 90th-percentile cost ($)
$610.08
Trials at or below budget (%)
86.25
Monte Carlo standard error of mean ($)
$1.00
Absolute difference between half-run means ($)
$0.97

Try another scenario

Items: name, minimum $, mode $, maximum $, quantile group or independent
Design,100,150,200,market Build,300,400,500,market
Simulation trials: 20–10000
2000
Unsigned 32-bit seed
42
Budget threshold ($)
600
Simulated mean total cost ($)
$552.16
Empirical median cost ($)
$551.73
Empirical 90th-percentile cost ($)
$633.11
Trials at or below budget (%)
77.85
Monte Carlo standard error of mean ($)
$1.36
Absolute difference between half-run means ($)
$1.57
Calculation method

Calculation method

Simulated mean total cost ($)

Draw triangular costs and sum items per trial. Shared named groups reuse one uniform quantile within a trial; independent rows use separate draws.

Empirical median cost ($)

Nearest-rank empirical 50th percentile.

Empirical 90th-percentile cost ($)

Nearest-rank empirical 90th percentile.

Trials at or below budget (%)

Fraction of totals ≤ the supplied budget, multiplied by 100.

Monte Carlo standard error of mean ($)

Sample standard deviation with n−1 denominator, divided by sqrt(trials).

Absolute difference between half-run means ($)

Compare first-half and second-half sample means as a simple convergence diagnostic.

Symbols and units
a
Items: name, minimum $, mode $, maximum $, quantile group or independent
b
Simulation trials: 20–10000
c
Unsigned 32-bit seed
d
Budget threshold ($)

Use the units shown. A list keeps the order in which you enter its values. The symbol ^ means “raised to the power of”.

Assumptions & limits

Assumptions & limits

  • A reproducible triangular-input simulation using an unsigned 32-bit LCG and open-interval uniform quantiles. Named groups represent perfect positive quantile dependence; arbitrary correlations are not inferred. Model uncertainty is separate from Monte Carlo sampling error. Up to 40 items and 10,000 trials.
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Further reading

NIST: triangular-input Monte Carlo example ↗

Background reading; this does not imply endorsement or independent review of SumFizz.

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