diff --git a/crates/typst-library/src/compute/calc.rs b/crates/typst-library/src/compute/calc.rs
index ee4261afe..7cfe24919 100644
--- a/crates/typst-library/src/compute/calc.rs
+++ b/crates/typst-library/src/compute/calc.rs
@@ -47,6 +47,7 @@ pub fn module() -> Module {
     scope.define("inf", f64::INFINITY);
     scope.define("nan", f64::NAN);
     scope.define("pi", std::f64::consts::PI);
+    scope.define("tau", std::f64::consts::TAU);
     scope.define("e", std::f64::consts::E);
     Module::new("calc").with_scope(scope)
 }
diff --git a/docs/reference/details.yml b/docs/reference/details.yml
index 8e9af3a0d..5b6b9ed0c 100644
--- a/docs/reference/details.yml
+++ b/docs/reference/details.yml
@@ -151,7 +151,7 @@ calculate: |
 
   These functions are part of the `calc` module and not imported by default. In
   addition to the functions listed below, the `calc` module also defines the
-  constants `pi`, `e`, `inf`, and `nan`.
+  constants `pi`, `tau`, `e`, `inf`, and `nan`.
 
 construct: |
   Construction of and conversions between values of different types.