It is not my impression that I am uniquely gifted at mathematics, nor do I think this is a particularly clever travel tip, but as I watch travelers calculate the cost of things by converting currency on calculators or asking a thousand times over “How much is this in dollars,” I suppose it is a [...]
It is not my impression that I am uniquely gifted at mathematics, nor do I think this is a particularly clever travel tip, but as I watch travelers calculate the cost of things by converting currency on calculators or asking a thousand times over “How much is this in dollars,” I suppose it is a travel tip that is needed.
I once thought that I was simply good and converting currency mentally, as I have always been able to do it quicker and more accurately than any person that I have ever traveled with, but I have recently realized that I have a trick.
The rule of 10s for converting currency in your head
Step one — Find out the going rate of the local currency in relation to the money that you use as your standard for determining cost. I am an American, so I use dollars. The Dominican Republic peso is currently pegged at 36 to 1 US dollar.
Step two — After figuring out how much of a local currency equals one unit of your standard currency multiply it by ten. 36 Dominican Republic Pesos times ten is 360. 360 pesos = $10.
Step three — Now multiply by 100. 3,600 Dominican Republic Pesos = $100.
Step four — Divide all of these amounts by 50%. So half of $1 is 18 pesos, half of $10 is 180 pesos, and $50 is 1,800 pesos.
Now I have the local currency figures for fifty cents, one dollar, five dollars, ten dollars, 50 dollars, and 100 dollars. I remember these amounts, they are just multiples of 10 of three amounts. This is all I need. I can now estimate costs by using these currency landmarks.
So if I find a product that is 400 Dominican Republic pesos I find the nearest currency landmark — 360 pesos, or $10. I now know that the amount that I am trying to figure out is forty pesos more than 10 US dollars. Forty pesos is a little over one dollar. Add these amounts together and you can estimate the price at $11.
If I find something that is 150 pesos, I know that this is 30 pesos less than five USD. 30 pesos is a little less than one dollar. I now know that what I am looking at costs around $4.
If I want to purchase something that costs 58 pesos, then I know that this amount is 22 pesos more than one dollar. I can therefore do a quick estimation and say that it is around $1.65.
If I want to buy something that costs 1,489 pesos, I can determine that this amount is 260 pesos shy of 50 dollars. 260 pesos is around $7. I now know that what I want is $43.
There is no such thing as an exact currency conversion at street level — relative values of money are always changing — so estimations are acceptable unless you are paying off a bet or something.
This is a simple way of converting currency, this is how I do it. This way works for me, maybe it will for you, too.
This is a VagabondJourney.com travel tip. As always, take it and use it, or break out your calculator, ask some nerd like me to tell you how much something is, or just don’t bother thinking about how much money you are spending.
Travel Tips — Budget Travel
About the Author: VBJ
I am the founder and editor of Vagabond Journey. He has been traveling the world since 1999, through 90 countries. I am the author of the book, Ghost Cities of China, and contributes to The Guardian, Forbes, Bloomberg, The Diplomat, the South China Morning Post, and other publications. VBJ has written 3636 posts on Vagabond Journey. Contact the author.
VBJ is currently in: Astoria, New York

February 10, 2010, 12:33 am
My daddy always told me that it’s best to forget about converting to dollars… instead just think in your new currency. If your daily budget is 100 quetzals, then if a hotel room costs 40 quetzals, well that’s ok. I find this better than converting to dollars… because if I start doing that, I get into this frame of mind where I think “oh, that’s only ____ dollars, I might as well spend that.”

February 10, 2010, 8:05 pm
My problem is with the mix of currency. For example: In the US, we use the decimal system of currency. On one side of the decimal point, you have paper bills, in increasing size. On the other side, you have coins, in decreasing size. It is easy to manage change and bills.
In Canada, on one side of the decimal point, you have coins. On the other side you have bills. And coins. So when you buy something, you have to decide whether to pull out bills, coins or whatever. WHO thunk up such a system?
Bob L

February 11, 2010, 12:45 pm
I used Canada as an example for Caitlin’s sake. I suppose no matter where you go, you always end up with traveler’s wallet anyway.
Bob L
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