I have to admit I’m pretty terrible with this one. My method of coping with travel-sized toiletries is stealing them from hotel bathrooms and randomly stocking up during Target shopping trips.
It was only when a friend asked me how I saved by using my own toiletries that I began to get curious. I mean, I knew it was probably the more cost-effective method given the volume of travel that I do. But I didn’t exactly know how cost-efficient it would be or ever bothered to figure it out.
Naturally, the only thing that made sense after that was making a spreadsheet to figure it all out. This basic spreadsheet calculator should help any traveler exactly how much they’re saving by plugging in a few key factors. (You might need to sign in to your Google account to see the template.)
How do I use this?
In order to figure out how you’re saving with your own bottles and products, there’s a couple of required data points. This would include the bottle set cost, how many bottles are in each set, the size of each bottle, the cost of product and how much product is in that bottle. To make it easy, cells that need input are highlighted in yellow. Once those factors are plugged in, the other variables will be calculated. The spreadsheet will then make a final calculation showing the cost of refilling a bottle.
The defaults are set to 100 mL (3.34 ounces), the TSA-approved carry-on size for liquids. One of the most common travel bottle sizes in the U.S. is 89 mL (at a flat 3 ounces), so double-check that. If it's not clear, toiletry size refers to the full-sized bottle capacity. Bottle size refers to the volume of the travel-sized bottle.
Though it’s impossible to calculate how much you’re saving without knowing how much you spend on travel-sized toiletries at the convenience store (and since I don’t keep track either, myself), I would guess I’m spending at least a dollar for every travel-sized mini I pick up at Target. If I use that assumption, you can quickly substitute the number of bottle refills for the cost you’d be spending at the store.
The math behind it
Let me explain that there’s a couple of variables in play here. First of all, the cost of the bottles is a fixed cost. I have a weird thing about spending a lot of money on plastic bottles that get manufactured in China for 1/100th of the price so given the choice between splurging on the GoToob or this cheap plastic tube set for $6, I’d pick the cheap plastic tube. Everyone’s different. This is me. Because there’s four of them, the cost is $1.50 per bottle.1
The second thing to consider is the cost of toiletries. Unfortunately, people get finicky about these things—everyone’s got their brands—so I’m going to use this Suave Professionals shampoo and conditioner set as my other variable. Though the cost is $11.12 on Amazon, the standard price in most Targets for this set is $3.79 which works out to roughly $1.90 per bottle. (Side note: It’s a great no-frills shampoo.)
Using the cost and calculating for the different bottle and product sizes, I can then get an idea of what each refill is costing me if I use what I already have at home. In each full bottle, there’s about 12.6 ounces or 373 mL of product. In a 3-ounce (88.72 mL) plastic tube, which is what I'm currently using, that’s enough to fill the bottle 4.2 times. If it was 3.33 (100 mL) bottle, I’d manage to get away with filling it 3.73 times.
If I use my personal preferences as an example, by the time I hit the 10th bottle refill, it’s costing me $6.03 instead of the $10 I’d be spending at Target for the same number of bottles. That’s 40% in savings. By the time I hit the 20th bottle refill, it’s costing me $10.57 for what would be costing me at least $20 in-store. That’s 50% in savings.
Obviously, the difference in savings only amplify the more you do this. It’s probably worth noting that you might be getting less product in a travel-sized mini at the store, too, since the bottle amounts all vary by manufacturer. So there you have it, travel geeks.