diff --git a/lib/std/math.zig b/lib/std/math.zig
index 8e08cacc4..714521357 100644
--- a/lib/std/math.zig
+++ b/lib/std/math.zig
@@ -10,6 +10,9 @@ pub const e = 2.71828182845904523536028747135266249775724709369995;
 /// Archimedes' constant (π)
 pub const pi = 3.14159265358979323846264338327950288419716939937510;
 
+/// Circle constant (τ)
+pub const tau = 2 * pi;
+
 /// log2(e)
 pub const log2e = 1.442695040888963407359924681001892137;