The question we get more than any other is some version of "how long will this last me?" The answer is printed on the front of the bottle. Most people just don't know that's what they're looking at.

The number on the label is the number of loads

True is 4x concentrated. One ounce is all most washable loads need. That's the whole dosing instruction, and it makes the math easy: a 50 fl. oz. bottle is 50 loads, and a 101 fl. oz. bottle is 101 loads.

So when you're standing in the laundry room wondering how much is left, tip the bottle and look at the ounces. Whatever is in there is that many loads. No guessing at capfuls.

How long a bottle lasts, by household

The second half of the math depends on who lives with you. Nobody counts their loads, so here's a rough guide. Adjust it to your house.

Those are the label numbers divided by loads per week and rounded to something you can plan around. If your house runs more loads than the row you picked, slide down a row.

Load size changes the math a little

An everyday load, the mixed basket of shirts, jeans, towels, and whatever the kids wore, is one ounce. Fill to the line on the cap and stop.

A full drum or a heavily soiled load takes a little more, and the label says so. Practice uniforms, work clothes, the sheets after somebody's been sick. If most of your loads are the big kind, take a week or two off the numbers above. If most of your loads are small, add a week or two.

One clarification for high-efficiency and top-loading machines: the directions say 1/8 cup. That's the same one ounce, measured a different way. It isn't more.

The mistake most people make when they switch

If you came to True from a regular detergent, you've been trained to fill the cap. Maybe most of the way, maybe all the way, depending on the brand and how much foam you like to see.

With a concentrated formula, that cap is too much. Filling it doesn't get clothes cleaner. It can leave residue, it takes longer to rinse, and it runs through the bottle far faster than it should. The line on the cap is one ounce. Pour to the line. If you've been pouring past it, your bottle has been lasting a fraction of what it could.

Cold water is fine

True works in all water temperatures. You don't need hot water to make one ounce do its job, and you don't need extra detergent to make up for cold. The one place hot water still earns its keep is the heavily soiled load, and even there the adjustment is a little more detergent, as the label says, not a capful.

Once you know your months, you know your date

Here's why we care about this math. Everybody runs out of detergent the same way: on a Sunday night, with a full hamper, halfway through a load. It's the one household product where the empty bottle costs you the most at the worst moment.

If you know your bottle is a two-month bottle in your house, you know your date. A subscription puts the next bottle on your porch before that date, on a schedule you set from the numbers above. You pick the bottle size and the cadence. You skip a delivery when you're stocked and pause when you travel. Change it anytime, no phone call.

That's the whole thing. One ounce, one load, and a bottle that shows up before you need it.

Set up your delivery to match your house