 # Exchange % formula

• Hello everyone!

I'm developing a tool with excel, but I don't know how to calculate the resource % in exchanges.

For example:

I sell 1.000.000 deut and I buy 40% met & 60%cry. If the exchange rates are 2,5:1,5:1 we have:

1kk deut for 714.286 met and 1.071.429 cry.

As you can see, 40% does not mean 0,4*1000. It's the 40% of the total: [714.286 : 1.071.429 = 40 : 60]

I don't know how to calculate this, is there someone who can help me?

OGame.it

Selling 1.000.000 deut. Buying 714.286 met and 1.071.429 crys. Exchange rates 2.5:1.5:1

same as yours already made • I forgot to mention that I used that tool to calculate, but I'm wondering about the formula behind those numbers

OGame.it

• You have to work backwards

You have D total deut. You want to trade it so you get X% metal and Y% crystal at 2.5:1.5:1

M is the total amount you will trade for metal.

So the total trade will end up with 2.5M and 1.5(D-M)

As we know the percentages, 2.5M = X/Y x 1.5(D-M)

Expand out - 2.5M = (1.5X/Y)D - (1.5X/Y)M

Move the Ms to one side - (2.5 +1.5X/Y) M = (1.5X/Y)D

Make the M on it's own - M = (1.5X/Y)D / (2.5+1.5X/Y)

Now plug X and Y and D (which you know - the amount of deut you want to trade and the ratio you want back) into the formula and you can calculate M from it.

It's not a pretty formula, but it works Edit - dammit the X and Y were the wrong way round - think it's right now...

Edit 2 - you can also change the trade rate inside the formula - so say you want the trade rate to be A:B:1

The formula is then M = (BXD/Y) / (A + BX/Y)

The post was edited 2 times, last by crispybits ().

• Desired Resources Ratio / Rate = Ratio in Deuterium Sold (RRiDS)

{30% , 70 % , 0% } / {2.5 , 1.5 , 1}
0.12 : 0.46666 : 0

Convert the RRiDS into a percentage

{0.12 , 0.46666 , 0 } / 0.58666
20.45%, 79.55% , 0% = Percentage of Deuterium Sold

*To verify

511,364 metal = 20.45% * 1,000,000 * 2.5
1,193,182 crystal = 79.55% * 1,000,000 * 1.5