**Easy calculating card equity / odds and pot odds**

So I've read various sites on how to calculate card equity /

odds. I just want to clarify the methods of calculation to be accurate and quick.

So just #outs *2, so 8 outs is 16% chance of hitting, although I read on one site add 1% to that (not explained why), so 17% chance on each street.

Another site says for >8 outs you should use the following formula:

(number of outs * 4) - (number of outs - 8) = Equity

So, 12*4-(12-8)= 44% for both street, or 22% for each.

compared to

12*2+1= 25%

assuming you're in an allin position 44% I guess, since I would prefer to calculate each street individually it'd be the 22%. I'm unsure of as to why you'd use this formula.

I don't know if this precision truly matters or if one is actually incorrect.

For card odds, correct me if I'm wrong, but it's 47 / # outs, so with 8 outs:

47 / 8 = 5.875 : 1. To add to that one site says you must subtract 1, for a reason it doesn't explain, so 4.875 : 1. (although that amount is 20.5%, so larger than the previous card equity).

Then comparing to

pot odds, 55 in the pot, villain bets 15 on the flop, so 70 total with 15 to call: 70 : 15 = ~4.7 : 1.

So in this case, assuming that 15 put him all in, I should be close to calling based solely on the math. If there will be another betting round, I would need to recalculate pot odds. Ex: now 70 in pot, he bets 15, that'd make it 5.66 :1 with a 5.75 :1 card odds.

To further confuse me, another site says again: Multiply outs by 4, then do the following: . 8*4=32, 100-32 = 68, then 68 / 32 = 2.1 : 1 odds according to this method. It doesn't clarify but obviously this is for the allin situation, so I'm guessing multiply that to 4.2 : 1 for individual streets.

I think I'm grasping the main concepts minus some weird quirks different places are saying you need to do, but the pod odds vs individual streets trips me up.

Sorry for the long post, thanks for the help.