How to convert this odds format

[monkeyspanker mo]

Many of the odds on this site are listed in this format: +148 -158 or +330, -370. Could someone please explain to me what these mean and how I would convert them to a decimal odds format.

Many thanks,

[THE PROFIT]

I'm pretty sure there's a thread in the think tank about that.

[Boner_18]

Decimal odds = IF(American odds <0 then 1-(100/American odds) else 1+(American odds/100))

For american odds a minus number is the amount you must lay to win 100 and a plus number is the to win for risking 100.