diff --git a/CMakeLists.txt b/CMakeLists.txt
index 5f17d88..8e49c19 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -516,12 +516,6 @@
 
 # After the tweaks for the compile settings, disable some warnings on MSVC.
 if (MSVC)
-  # On MSVC, math constants are not included in <cmath> or <math.h> unless
-  # _USE_MATH_DEFINES is defined [1].  As we use M_PI in the examples, ensure
-  # that _USE_MATH_DEFINES is defined before the first inclusion of <cmath>.
-  #
-  # [1] https://msdn.microsoft.com/en-us/library/4hwaceh6.aspx
-  add_compile_definitions(_USE_MATH_DEFINES)
   # Insecure standard library functions
   add_compile_definitions(_CRT_SECURE_NO_WARNINGS)
   # std::numeric_limits<T>::has_denorm is deprecated in C++23
diff --git a/examples/ellipse_approximation.cc b/examples/ellipse_approximation.cc
index 5f31b12..eefc72d 100644
--- a/examples/ellipse_approximation.cc
+++ b/examples/ellipse_approximation.cc
@@ -396,7 +396,7 @@
   //
   // Initialize `X` to points on the unit circle.
   VectorXd w(num_segments + 1);
-  w.setLinSpaced(num_segments + 1, 0.0, 2.0 * M_PI);
+  w.setLinSpaced(num_segments + 1, 0.0, 2.0 * ceres::constants::pi);
   w.conservativeResize(num_segments);
   MatrixXd X(num_segments, 2);
   X.col(0) = w.array().cos();
diff --git a/examples/more_garbow_hillstrom.cc b/examples/more_garbow_hillstrom.cc
index 35936f4..b2fe61b 100644
--- a/examples/more_garbow_hillstrom.cc
+++ b/examples/more_garbow_hillstrom.cc
@@ -223,7 +223,7 @@
   const T x1 = x[0];
   const T x2 = x[1];
   const T x3 = x[2];
-  const T theta = (0.5 / M_PI)  * atan(x2 / x1) + (x1 > 0.0 ? 0.0 : 0.5);
+  const T theta = (0.5 / constants::pi)  * atan(x2 / x1) + (x1 > 0.0 ? 0.0 : 0.5);
   residual[0] = 10.0 * (x3 - 10.0 * theta);
   residual[1] = 10.0 * (sqrt(x1 * x1 + x2 * x2) - 1.0);
   residual[2] = x3;
diff --git a/examples/slam/pose_graph_2d/normalize_angle.h b/examples/slam/pose_graph_2d/normalize_angle.h
index d54547a..0602878 100644
--- a/examples/slam/pose_graph_2d/normalize_angle.h
+++ b/examples/slam/pose_graph_2d/normalize_angle.h
@@ -41,9 +41,9 @@
 template <typename T>
 inline T NormalizeAngle(const T& angle_radians) {
   // Use ceres::floor because it is specialized for double and Jet types.
-  T two_pi(2.0 * M_PI);
+  T two_pi(2.0 * constants::pi);
   return angle_radians -
-         two_pi * ceres::floor((angle_radians + T(M_PI)) / two_pi);
+         two_pi * ceres::floor((angle_radians + T(constants::pi)) / two_pi);
 }
 
 }  // namespace ceres::examples
diff --git a/include/ceres/ceres.h b/include/ceres/ceres.h
index 5beec9c..51f9d89 100644
--- a/include/ceres/ceres.h
+++ b/include/ceres/ceres.h
@@ -39,8 +39,8 @@
 #include "ceres/autodiff_first_order_function.h"
 #include "ceres/autodiff_manifold.h"
 #include "ceres/conditioned_cost_function.h"
-#include "ceres/context.h"
 #include "ceres/constants.h"
+#include "ceres/context.h"
 #include "ceres/cost_function.h"
 #include "ceres/cost_function_to_functor.h"
 #include "ceres/covariance.h"
diff --git a/include/ceres/constants.h b/include/ceres/constants.h
index 8558160..584b669 100644
--- a/include/ceres/constants.h
+++ b/include/ceres/constants.h
@@ -36,6 +36,7 @@
 namespace ceres::constants {
 template <typename T>
 inline constexpr T pi_v(3.141592653589793238462643383279502884);
+inline constexpr double pi = pi_v<double>;
 }  // namespace ceres::constants
 
 #endif  // CERES_PUBLIC_CONSTANTS_H_
diff --git a/include/ceres/internal/sphere_manifold_functions.h b/include/ceres/internal/sphere_manifold_functions.h
index 184edf9..4793442 100644
--- a/include/ceres/internal/sphere_manifold_functions.h
+++ b/include/ceres/internal/sphere_manifold_functions.h
@@ -32,6 +32,7 @@
 #ifndef CERES_PUBLIC_INTERNAL_SPHERE_MANIFOLD_HELPERS_H_
 #define CERES_PUBLIC_INTERNAL_SPHERE_MANIFOLD_HELPERS_H_
 
+#include "ceres/constants.h"
 #include "ceres/internal/householder_vector.h"
 
 // This module contains functions to compute the SphereManifold plus and minus
@@ -122,7 +123,7 @@
   const double hy_norm = hy.template head<TangentSpaceDim>(tangent_size).norm();
   if (hy_norm == 0.0) {
     y_minus_x->setZero();
-    y_minus_x->data()[tangent_size - 1] = y_last >= 0 ? 0.0 : M_PI;
+    y_minus_x->data()[tangent_size - 1] = y_last >= 0 ? 0.0 : constants::pi;
   } else {
     *y_minus_x = std::atan2(hy_norm, y_last) / hy_norm *
                  hy.template head<TangentSpaceDim>(tangent_size);
diff --git a/include/ceres/rotation.h b/include/ceres/rotation.h
index 7d2d79e..0cccfa7 100644
--- a/include/ceres/rotation.h
+++ b/include/ceres/rotation.h
@@ -610,7 +610,7 @@
   //   [-pi, pi) x [0, pi / 2) x [-pi, pi)
   // which is enforced here
   if constexpr (EulerSystem::kIsProperEuler) {
-    const T kPi(constants::pi_v<double>);
+    const T kPi(constants::pi);
     const T kTwoPi(2.0 * kPi);
     if (euler[1] < T(0.0) || ea[1] > kPi) {
       euler[0] += kPi;
diff --git a/internal/ceres/autodiff_benchmarks/brdf_cost_function.h b/internal/ceres/autodiff_benchmarks/brdf_cost_function.h
index 87842c0..41cfcfa 100644
--- a/internal/ceres/autodiff_benchmarks/brdf_cost_function.h
+++ b/internal/ceres/autodiff_benchmarks/brdf_cost_function.h
@@ -35,6 +35,8 @@
 #include <Eigen/Core>
 #include <cmath>
 
+#include "ceres/constants.h"
+
 namespace ceres {
 
 // The brdf is based on:
@@ -139,7 +141,7 @@
     const T gr = cggxn_dot_l * cggxn_dot_v;
 
     const Vec3 result_no_cosine =
-        (T(1.0 / M_PI) * Lerp(fd, ss, subsurface) * c + f_sheen) *
+        (T(1.0 / constants::pi) * Lerp(fd, ss, subsurface) * c + f_sheen) *
             (T(1) - metallic) +
         gs * fs * ds +
         Vec3(T(0.25), T(0.25), T(0.25)) * clearcoat * gr * fr * dr;
@@ -177,11 +179,11 @@
     T result = T(0);
 
     if (a >= T(1)) {
-      result = T(1 / M_PI);
+      result = T(1 / constants::pi);
     } else {
       const T a2 = a * a;
       const T t = T(1) + (a2 - T(1)) * n_dot_h * n_dot_h;
-      result = (a2 - T(1)) / (T(M_PI) * T(log(a2) * t));
+      result = (a2 - T(1)) / (T(constants::pi) * T(log(a2) * t));
     }
     return result;
   }
@@ -192,7 +194,7 @@
                      const T& h_dot_y,
                      const T& ax,
                      const T& ay) const {
-    return T(1) / (T(M_PI) * ax * ay *
+    return T(1) / (T(constants::pi) * ax * ay *
                    Square(Square(h_dot_x / ax) + Square(h_dot_y / ay) +
                           n_dot_h * n_dot_h));
   }
diff --git a/internal/ceres/autodiff_manifold_test.cc b/internal/ceres/autodiff_manifold_test.cc
index 6e5c4fc..c687719 100644
--- a/internal/ceres/autodiff_manifold_test.cc
+++ b/internal/ceres/autodiff_manifold_test.cc
@@ -32,6 +32,7 @@
 
 #include <cmath>
 
+#include "ceres/constants.h"
 #include "ceres/manifold.h"
 #include "ceres/manifold_test_utils.h"
 #include "ceres/rotation.h"
@@ -197,7 +198,7 @@
 
   for (int i = 0; i < 3; ++i) {
     Vector delta = Vector::Zero(3);
-    delta[i] = M_PI / 2;
+    delta[i] = constants::pi / 2;
     Vector x_plus_delta = Vector::Zero(4);
     EXPECT_TRUE(manifold.Plus(x.data(), delta.data(), x_plus_delta.data()));
 
@@ -285,7 +286,7 @@
     const Vector y = RandomQuaternion();
     Vector delta = Vector::Random(3);
     delta.normalize();
-    delta *= (M_PI - 1e-6);
+    delta *= (constants::pi - 1e-6);
     EXPECT_THAT(manifold, QuaternionPlusIsCorrectAt(x, delta));
     EXPECT_THAT_MANIFOLD_INVARIANTS_HOLD(manifold, x, delta, y, kTolerance);
   }
diff --git a/internal/ceres/dynamic_sparsity_test.cc b/internal/ceres/dynamic_sparsity_test.cc
index c1b971d..0c29595 100644
--- a/internal/ceres/dynamic_sparsity_test.cc
+++ b/internal/ceres/dynamic_sparsity_test.cc
@@ -383,7 +383,7 @@
   //
   // Initialize `X` to points on the unit circle.
   Vector w(num_segments + 1);
-  w.setLinSpaced(num_segments + 1, 0.0, 2.0 * M_PI);
+  w.setLinSpaced(num_segments + 1, 0.0, 2.0 * constants::pi);
   w.conservativeResize(num_segments);
   Matrix X(num_segments, 2);
   X.col(0) = w.array().cos();
diff --git a/internal/ceres/manifold_test.cc b/internal/ceres/manifold_test.cc
index dc0fe53..33f9386 100644
--- a/internal/ceres/manifold_test.cc
+++ b/internal/ceres/manifold_test.cc
@@ -36,6 +36,7 @@
 #include <utility>
 
 #include "Eigen/Geometry"
+#include "ceres/constants.h"
 #include "ceres/dynamic_numeric_diff_cost_function.h"
 #include "ceres/internal/eigen.h"
 #include "ceres/internal/port.h"
@@ -504,7 +505,7 @@
 
   for (int i = 0; i < 3; ++i) {
     Vector delta = Vector::Zero(3);
-    delta[i] = M_PI / 2;
+    delta[i] = constants::pi / 2;
     Vector x_plus_delta = Vector::Zero(4);
     EXPECT_TRUE(manifold.Plus(x.data(), delta.data(), x_plus_delta.data()));
 
@@ -598,7 +599,7 @@
     const Vector y = RandomQuaternion();
     Vector delta = Vector::Random(3);
     delta.normalize();
-    delta *= (M_PI - 1e-6);
+    delta *= (constants::pi - 1e-6);
     EXPECT_THAT(manifold, QuaternionManifoldPlusIsCorrectAt(x, delta));
     EXPECT_THAT_MANIFOLD_INVARIANTS_HOLD(manifold, x, delta, y, kTolerance);
   }
@@ -669,7 +670,7 @@
     const Vector y = RandomQuaternion();
     Vector delta = Vector::Random(3);
     delta.normalize();
-    delta *= (M_PI - 1e-6);
+    delta *= (constants::pi - 1e-6);
     EXPECT_THAT(manifold, EigenQuaternionManifoldPlusIsCorrectAt(x, delta));
     EXPECT_THAT_MANIFOLD_INVARIANTS_HOLD(manifold, x, delta, y, kTolerance);
   }
@@ -732,7 +733,7 @@
   }
 
   {
-    double delta[1]{M_PI};
+    double delta[1]{constants::pi};
     Eigen::Vector2d y = Eigen::Vector2d::Zero();
     EXPECT_TRUE(manifold.Plus(x.data(), delta, y.data()));
     const Eigen::Vector2d gtY = -Eigen::Vector2d::UnitY();
@@ -740,7 +741,7 @@
   }
 
   {
-    double delta[1]{2.0 * M_PI};
+    double delta[1]{2.0 * constants::pi};
     Eigen::Vector2d y = Eigen::Vector2d::Zero();
     EXPECT_TRUE(manifold.Plus(x.data(), delta, y.data()));
     const Eigen::Vector2d gtY = Eigen::Vector2d::UnitY();
@@ -761,7 +762,7 @@
   }
 
   {
-    Eigen::Vector2d delta{M_PI, 0.0};
+    Eigen::Vector2d delta{constants::pi, 0.0};
     Eigen::Vector3d y = Eigen::Vector3d::Zero();
     EXPECT_TRUE(manifold.Plus(x.data(), delta.data(), y.data()));
     const Eigen::Vector3d gtY = -Eigen::Vector3d::UnitZ();
@@ -769,7 +770,7 @@
   }
 
   {
-    Eigen::Vector2d delta{2.0 * M_PI, 0.0};
+    Eigen::Vector2d delta{2.0 * constants::pi, 0.0};
     Eigen::Vector3d y = Eigen::Vector3d::Zero();
     EXPECT_TRUE(manifold.Plus(x.data(), delta.data(), y.data()));
     const Eigen::Vector3d gtY = Eigen::Vector3d::UnitZ();
@@ -785,7 +786,7 @@
   }
 
   {
-    Eigen::Vector2d delta{0.0, M_PI};
+    Eigen::Vector2d delta{0.0, constants::pi};
     Eigen::Vector3d y = Eigen::Vector3d::Zero();
     EXPECT_TRUE(manifold.Plus(x.data(), delta.data(), y.data()));
     const Eigen::Vector3d gtY = -Eigen::Vector3d::UnitZ();
@@ -793,7 +794,7 @@
   }
 
   {
-    Eigen::Vector2d delta{0.0, 2.0 * M_PI};
+    Eigen::Vector2d delta{0.0, 2.0 * constants::pi};
     Eigen::Vector3d y = Eigen::Vector3d::Zero();
     EXPECT_TRUE(manifold.Plus(x.data(), delta.data(), y.data()));
     const Eigen::Vector3d gtY = Eigen::Vector3d::UnitZ();
@@ -809,7 +810,7 @@
   }
 
   {
-    Eigen::Vector2d delta = Eigen::Vector2d(1, 1).normalized() * M_PI;
+    Eigen::Vector2d delta = Eigen::Vector2d(1, 1).normalized() * constants::pi;
     Eigen::Vector3d y = Eigen::Vector3d::Zero();
     EXPECT_TRUE(manifold.Plus(x.data(), delta.data(), y.data()));
     const Eigen::Vector3d gtY = -Eigen::Vector3d::UnitZ();
@@ -832,7 +833,7 @@
   {
     double delta[1];
     const Eigen::Vector2d y(-1, 0);
-    const double gtDelta{M_PI};
+    const double gtDelta{constants::pi};
     EXPECT_TRUE(manifold.Minus(y.data(), x.data(), delta));
     EXPECT_LT(std::abs(delta[0] - gtDelta), kTolerance);
   }
@@ -853,7 +854,7 @@
   {
     Eigen::Vector2d delta;
     const Eigen::Vector3d y(-1, 0, 0);
-    const Eigen::Vector2d gtDelta(0.0, M_PI);
+    const Eigen::Vector2d gtDelta(0.0, constants::pi);
     EXPECT_TRUE(manifold.Minus(y.data(), x.data(), delta.data()));
     EXPECT_LT((delta - gtDelta).norm(), kTolerance);
   }
diff --git a/internal/ceres/rotation_test.cc b/internal/ceres/rotation_test.cc
index 87f9de7..f1ea071 100644
--- a/internal/ceres/rotation_test.cc
+++ b/internal/ceres/rotation_test.cc
@@ -53,7 +53,7 @@
 namespace ceres {
 namespace internal {
 
-inline constexpr double kPi = constants::pi_v<double>;
+inline constexpr double kPi = constants::pi;
 const double kHalfSqrt2 = 0.707106781186547524401;
 
 // A tolerance value for floating-point comparisons.