How much underwear to pack? The travel underpants sweetspot!

I don’t care about clothes. However, I tend to spend money on one specific piece of clothing. As a guy, I think it is essential to have plenty of underwear, specifically, comfortable underpants. But the question that haunts me with every trip is: how much underwear to pack?

You don’t want to find yourself bringing too few and doing desperate sink laundry. But overpacking takes up precious space in your backpack or suitcase. So, what’s the sweet spot?

I spent hours researching this before writing because I have my own packing habits, but I wanted to see if someone else had cracked the code. I found tables, graphics, and mathematical formulas online. However, almost all of them were female-oriented. So, this one is for the guys!

Here is the ultimate guide and mathematical formula for packing men’s underwear, whether you’re heading on a quick city trip or a multi-month backpacking adventure.

The quick reference chart: how many to pack

Don’t want to do the math? I get it. If you’re packing for a standard trip with no mid-trip laundry planned, here is the cheat sheet for the exact amount of underwear you need to bring:

• 3-day trip: 4 to 5 pairs
• 5-day trip: 6 to 7 pairs
• 7-day trip (1 week): 9 to 10 pairs
• 14-day trip (2 weeks): 10 to 12 pairs (assuming you do laundry once midway through!)

The fabric factor: what you pack changes how much you pack

Before we get to the fun math formulas, we have to talk about materials. The fabric of your underwear dictates how many pairs you actually need to pack.

Merino wool & synthetic blends If you invest in high-quality travel underwear made of merino wool or synthetic moisture-wicking materials, you can pack significantly less. These materials are naturally odor-resistant and dry incredibly fast. You can wear a pair, wash it in the hotel sink with some soap, wring it out, and it will be bone-dry by morning. If you pack these, you really only need 3 or 4 pairs for an indefinite trip.

Standard cotton. If you are packing standard cotton underpants, you need to follow my formulas below. Cotton traps sweat, holds onto odors, and takes forever to air-dry. If you wash a cotton pair in a sink, you’ll be packing a damp, heavy piece of clothing into your bag the next day. Pack more cotton!

A simple formula for how many underpants to bring

If you’re bringing standard cotton underwear on a normal, relaxed holiday, the most straightforward formula is this:

(Amount of days x 1) + (amount of days x 0.5) = amount of underpants to bring

Let’s do this for a 5-day city trip as an example:

(5 x 1) + (5 x 0.5) = 5 + 2.5 = 7.5

This leaves you with the choice to bring 7 or 8 pairs. I like to play it safe and take 8 with me. But seven should be plenty.

The packing formula for active travelers

Say you want to go skiing, hiking, or do any other type of active trip. It’s best to pack a couple more, as sweaty underwear is the absolute downfall of feeling comfortable under your clothes.

(Amount of days x 1.25) + (amount of days x 0.5) = amount of underpants to bring

Let’s do this for a 5-day skiing trip as an example:

(5 x 1.25) + (5 x 0.5) = 6.25 + 2.5 = 8.75 (round up to 9 pairs)

Let’s do this for a 12-day active hiking trip:

(12 x 1.25) + (12 x 0.5) = 15 + 6 = 21 pairs (Wait, 21 is a lot! If your trip is this long, you need the next formula).

The packing formula for long travels

Let’s assume you’re going on a trip that’s longer than two or three weeks. Because there is a simple thing you can do to save space in your backpack: do laundry.

(Days in your laundry cycle x 1) + (Days in your laundry cycle x 0.5) = amount to bring

For example, let’s assume you will do your laundry weekly (as you probably should to keep your backpack smelling fresh).

(7 x 1) + (7 x 0.5) = 7 + 3.5 = 10.5

Even though you can do laundry, there is always a need for a backup pair. Not one week will be the same. And if you are anything like me, your grand plan to do laundry weekly is probably overreached. So let’s use those extra pairs of underwear to catch up on laundry safely from time to time. Pack 11 pairs.

Space-saving hack: how to pack underwear compactly

If you’re following my formulas, you might be looking at a pile of 8 to 11 pairs of underwear, wondering how they will fit in your bag. The trick is the ranger roll.

Here is how you do it step-by-step:

1. Lay your underwear flat on a bed or table.
2. Fold the waistband inside out, creating a 2-inch cuff at the top.
3. Fold the left side into the middle, then fold the right side over the left (like a brochure).
4. Start from the bottom crotch and roll it tightly upwards toward the waistband.
5. Once you reach the top, flip the inside-out cuff over the entire roll.

You now have a tight, secure little burrito of underwear that won’t unroll in your bag and fits perfectly inside your packing cubes!

Now I am curious, though. What’s your formula or way of thinking when packing for a trip? Let me know in the comments!