% Spent
Let's start with the friendliest formula in project management. "% Spent" simply tells you how much of your total money pot you have already used up, expressed as a percentage. Before we go further, two quick terms: "AC" stands for Actual Cost, which is the real money you have actually spent on the project so far. "BAC" stands for Budget at Completion, which is the total amount of money you were approved to spend on the whole project from start to finish.
To calculate it, you take the money you have spent so far (AC), divide it by the total budget you were given (BAC), and multiply by 100 to turn the answer into a percentage. That's it — it's just one number divided by another and dressed up as a percent.
Reading the result is easy: a low percentage (say 20%) means you have only used a small slice of your money, while a high percentage (say 90%) means most of your budget is already gone. On its own this number does NOT tell you whether that spending is good or bad — for that you'd compare it to how much work is actually done. Project managers use % Spent as a quick, gut-check dashboard number to sense how far into the wallet they are, and it becomes powerful when placed next to progress measures like % Complete.
Think of it like watching the fuel gauge on a road trip. The gauge only tells you how much gas you've burned, not whether you're near your destination — you have to glance at the map (your actual progress) to know if you're on track.
Imagine your project's total approved budget (BAC) is $200,000. Three months in, your finance report shows you have actually spent (AC) $50,000 so far. You calculate: $50,000 ÷ $200,000 = 0.25, then 0.25 × 100 = 25%. So you have spent 25% of your total budget. If your work is also about 25% finished, that feels balanced; but if only 10% of the work is done, that 25% spent is an early warning that money is disappearing faster than progress.
Every PMP formula explained free — plus worked examples and practice in PMP Math, and full timed mocks in the simulator.