diff --git a/README.md b/README.md
index 902f050..a239b6d 100644
--- a/README.md
+++ b/README.md
@@ -1,3 +1,32 @@
 # Measurement
 
 Adds quantities and units to rust to allow unit safe computation
+
+## Define new quantity
+
+### Base Quantity
+
+```rust
+quantity! {
+    name: Time,
+    base_unit: Second,
+    units: {
+        Second:      1e+0,
+        Millisecond: 1e-3,
+    }
+}
+```
+
+### Derived Quantity
+
+```rust
+quantity! {
+    name: Velocity,
+    base_unit: MeterPerSecond,
+    units: {
+        MeterPerSecond: 1,
+        KilometerPerHour: 3.6,
+    },
+    derive: Length / Time,
+}
+```