Multiple Income Stream Calculator

A 3,500 salary, 800 of freelance work, 300 of dividends and 400 from rentals sums to 5,000 a month, or 60,000 a year. The salary is exactly 70% of that total, and if it paused the remaining streams would still deliver 1,500 a month. That second figure is the one the tool is built around: the total says how much comes in, and the concentration figures say how much of it depends on a single source.

What the result means

The primary result is the monthly total. The rows beneath it give the annual figure, the largest single source in cash and as a percentage, and what would remain each month if that largest source paused. The tool also flags concentration in the primary label itself, switching to a concentrated reading when the largest source exceeds 70% of the total. The threshold is strict: at the loaded figures the salary is exactly 70.00% and is not flagged, while raising it to 3,550 takes the share to 70.30% and does flag it.

Why diversification matters

A household drawing everything from one source has no income at all if that source stops, which is what the "if largest pauses" row measures. Additional streams reduce that exposure whether or not they are large, and some of them behave differently under stress: investment and rental income generally continue while employment income is being replaced, whereas a second job in the same sector may stop for the same reason the first one did. Equal splits are not the point. What the arithmetic shows is how much would still arrive, which can then be set against what actually has to be paid.

Quick example

With source A at 3,500, source B at 800, source C at 300 and source D at 400, the total is 5,000 a month and 60,000 a year. The largest source is 3,500, or 70.00% of the total, and 1,500 would remain each month if it stopped. Changing the mix without changing the total shows what the concentration figures are measuring: four equal sources of 1,250 give the same 5,000 total, but the largest share falls to 25.00% and 3,750 would remain if one paused, while a single source of 5,000 gives the same total again with a 100.00% share and nothing remaining.

Which inputs matter most

Every input carries identical weight in the total, since the calculation is a sum: an extra 100 in any field adds 100 to the monthly figure and 1,200 to the annual one. Where they differ entirely is in the concentration rows, which depend on how the same total is distributed rather than on its size. That distinction is the reason the four fields exist at all. A single field would produce the same headline number, and the split is what allows the largest share and the remaining-income figure to be calculated. Aggregating several small sources into one field is fine for the total but overstates concentration, because the combined bucket can become the largest source when none of its parts is.

What's happening under the hood

The monthly total is the sum of the four sources, and the annual total multiplies it by twelve. Each source's share is that source divided by the total. Concentration is flagged when the largest share exceeds 70%, which is a rule-of-thumb marker rather than a derived threshold. Two consequences of that follow. The threshold is strictly greater than 70%, so a share of exactly 70% is not flagged. And because the flag looks only at the single largest source, two sources at 45% each would leave 55% dependent on one of them without triggering anything, which is why the largest-share percentage is more informative than the flag on its own.

Why small rate shifts add up

Small differences in how income is distributed change the concentration reading far more than they change the total. Moving 100 a month from the salary field into any other source leaves the 5,000 total untouched while taking the largest share from 70.00% to 68.00% and lifting the remaining-income figure from 1,500 to 1,600. That is the whole distinction between the headline number and the resilience figures beneath it: the first responds to size, the second responds only to shape.