Homemade Laundry Detergent Powder: 5 Steps and the Right Dose

Three cups of laundry powder at 2 tablespoons a load covers 24 loads.

And that’s before you count the grated bar.

Below is a homemade laundry detergent powder recipe in 5 steps, with the right dose, a no-borax swap and cost math for your receipts.

• Best for: anyone with a top-load or HE washer and a box grater. Skip it if you want pods.
• Cost: 4 grocery-store boxes and 1 bar, each enough for several batches.
• Payoff: about 24 loads per batch at 2 tablespoons, closer to 48 at 1 tablespoon.
• Time: Same day.
• First step: Search your grocery store’s app for “super washing soda.”

How to Make Homemade Laundry Detergent Powder Step by Step

Homemade laundry detergent powder takes 5 steps: grate the soap, blend it fine, measure the powders, mix them and store the batch dry. Work near an open window, because fine powders puff up when you pour them.

Step 1: Grate the Bar Soap

Grate one 5-ounce bar on the fine side of a box grater. Fels-Naptha, Zote, Ivory and castile soap all work, so pick the cheapest bar you can find.

Finer shreds dissolve better, especially in cold water. Pick an unscented bar if you’d rather skip added fragrances and dyes.

Step 2: Blend the Soap Fine

Pulse the grated soap in a food processor with the washing soda until it looks like sand. The washing soda keeps the shreds from gumming up the blades.

A food processor you cook with is fine, as long as you wash it well afterward.

Step 3: Measure the Washing Soda, Borax and Baking Soda

Measure 1 cup each of washing soda, borax and baking soda. Washing soda is sodium carbonate, not baking soda, and the two chemicals clean differently, so don’t swap them.

Washing soda does the heavy cleaning, borax boosts the soap on stains and baking soda helps with odors.

Step 4: Mix Everything in a Sealed Container

Pour all 4 ingredients into a lidded container and shake the mixture for a minute. Let the dust settle before you open it.

Step 5: Label and Store It Dry

Store the batch sealed and labeled like any laundry chemicals, out of reach of kids and pets. Moisture makes it clump, so keep it away from steam.

Drop a tablespoon scoop inside, so you measure the same dose every time.

How Much Homemade Laundry Powder to Use Per Load

Homemade laundry powder needs only 1 to 2 tablespoons per load. Use 2 tablespoons in a top-load washer and 1 in an HE or front-load washer:

At those doses, one batch makes about 24 top-load loads or 48 HE loads, counting only the 3 cups of powders.

For cold washes, stir the dose into a cup of hot water first. That one habit stops the white specks undissolved soap leaves behind.

Is Homemade Laundry Powder Safe for HE Washers?

Homemade laundry powder makes very few suds, which is what an HE washing machine needs. Check your washer’s manual first, though, because some makers ask for HE-labeled detergent.

Put 1 tablespoon straight into the drum, then add the clothes. Why skip the drawer?

Dry powder can cake there before water reaches it.

Is It Really Cheaper to Make Your Own Laundry Detergent?

Homemade laundry detergent powder is cheaper only when its cost per load beats your current detergent’s, and a receipt tells you in 2 minutes. Here’s the math:

1. Note the price and size of each box and the bar.
2. Work out each box’s share used in one batch.
3. Add the shares and divide by 24 loads.
4. Divide your store detergent’s price by the loads on its label.

Say your share of the ingredients comes to $6, a made-up figure for this example. $6 divided by 24 loads is 25 cents a load, so any store detergent above that costs you more.

Count the grater and bucket in your DIY math too, though you only buy those once.

Prefer pouring to grating? The homemade liquid version is one more of the easy homemade cleaners you can mix yourself.

Recipe Variations: No Borax, No Bar Soap and Scented

Homemade laundry detergent powder still works without borax, without bar soap or with added scent, using the same 5-step method. Here are 3 common swaps:

• No borax: use more washing soda, as in this borax-free 3-ingredient mix.
• No bar soap: mix washing soda, baking soda, Epsom salt and sea salt, like this natural detergent recipe.
• Scented: stir in essential oils instead of synthetic fragrances, or try these best-smelling recipes.

The 3-ingredient laundry detergent skips the baking soda. Try one swap at a time to see what each change does.

Why Homemade Laundry Soap Leaves Residue

Homemade laundry soap leaves residue when the grated soap doesn’t fully dissolve or when hard water reacts with it, leaving clothes stiff. Bar soap is soap, not a synthetic detergent, so hard water affects it more.

The fix: grate finer, dissolve the dose in hot water and never use more than 2 tablespoons. If dark fabrics still look dull, add a vinegar rinse at the right vinegar-to-water ratio.

Fixing residue beats switching recipes, and it’s the kind of small habit that sticks in frugal living.