How big a buffer?

The average cost of your risks is the wrong number to budget — a risk either happens or it doesn't, and a bad year is several landing at once. Give each one a chance and a cost range, and a Monte CarloEach run rolls every risk: it happens or it doesn't by its probability, and if it does, its cost is drawn from your low / likely / high range. Ten thousand runs build the full distribution of total exposure. builds the spread of total exposure — so you can size the reserve that covers you most of the time, not just on average.

Risk register
Each risk is a chance × a cost range, rolled up across the period
Expected exposure ≈ €18 417The probability-weighted average cost across all risks — what you'd lose over the period on average if you ran it many times. The buffer below covers a bad year, not an average one. across 4 risks.
Forecast10,000 simulations
≤ €35 042

Set aside €35 042 and you're covered against the year's risks 85% of the time.

P85
€0€94 712
ConfidenceHold at most
50%confident
≤ €16 477
85%confident
≤ €35 042
95%confident
≤ €47 297
Seeded from your inputs — this link reproduces the exact same forecast.