A 26-year-old woman earning $100,000 stands to lose more than a million over her lifetime if she stays home for five years.

Is it really worth it to keep working when childcare is eating up my entire paycheck?

If you’re a working mom, chances are you’ve asked yourself this question a time or 10,000.

It’s no secret that childcare costs are prohibitively expensive—more than college tuition in many states. Paying $20,000 a year for daycare doesn’t make much sense when your take-home pay (after taxes and commuting) barely covers the cost. Or so the reasoning goes.

Michael Madowitz, an economist at the Center for American Progress, a progressive research and advocacy organization, says families often forget the long-term picture when making these calculations. So he developed a calculator that does just that.

In addition to the wages moms and dads lose when they’re not working, they also lose the chance to receive raises and to sock away retirement savings. And because the effects are cumulative, they add up over time to a whole lot of money.

For example, a 26-year-old mom making $44,148 (the median pay in the U.S.), will lose her salary in wages for taking a year off. But she will also lose $64,393 in wage growth (the cumulative effect of time off on future earnings), as well as $52,945 in retirement assets and benefits. (Since the interest on 401(k) plan contributions compound over time, even a small break equals a big dent in long-term benefits.)

Want to run the numbers for yourself? The calculator uses a variety of factors (gender, current age, salary, age when you started working full-time, age you plan to take time off for caregiving and years planned to be out of the labor force) to determine how much you'd lose, down to the dollar. Click here to try it out.