diff --git a/docs/zr_manual.htm b/docs/zr_manual.htm
index ea34835..edf0ac5 100644
--- a/docs/zr_manual.htm
+++ b/docs/zr_manual.htm
@@ -2563,7 +2563,7 @@ tune game balance.
fifth player. To get the percentage you need to do ratio / player slots.
Like 5 / 24 = 0.20 ⇒ 20% infection rate.
Conversion formula from percent to ratio:
- ratio = (percent / 100) * player slots
+ ratio = player slots - ((percent / 100) * player slots)
Decimals are stripped from the ratio because it's a integer value.
Options:
0 or a positive number up to max server slots