You don’t need to replace all your income. Here’s the number you actually need.

Somewhere along the way, the financial industry convinced everyone that retirement means replacing 100% of your paycheck. Which is a little strange, because retired-you isn’t commuting, isn’t saving for retirement anymore, and — if you’ve done this right — isn’t making a mortgage payment either.

Translation: you probably need less than you think. Not nothing. But less.

That’s what the income replacement ratio measures — the percentage of your working income you’ll actually replace once you stop working. Most people land somewhere between 70% and 80%. But “most people” isn’t you, so let’s find your number.

Here’s how to use the Income Replacement Calculator:

Replacement ratio — Start here. Enter what you make now and what you expect in retirement, and it shows the percentage of your income you’re on track to replace. The gauge fills up, your target sits right on it, done.

Income gap — This one does the uncomfortable math for you: the exact dollars you’re short (or ahead) each year, and what that adds up to over a full retirement. Better to know now than to find out at 72.

Savings needed — Working backward. It tells you what to actually save each year to hit your target, based on your timeline and what you’ve already got stashed.

A few honest caveats: this is a planning tool, not a crystal ball. It doesn’t discount for inflation or predict what the market’s going to do — nobody can, and anyone who says otherwise is selling something. Think of it as a flashlight, not a GPS. Enough to see the path, not a turn-by-turn guarantee.

But here’s the thing. A number you can see is a number you can plan around. A vague “am I going to be okay?” is a lot scarier than a screen that says “here’s the gap, and here’s the fix.”

Pour yourself something. Plug in your numbers. Let’s find out where you actually stand.