diff --git a/README.md b/README.md
index ddcc0a8..e8685ff 100644
--- a/README.md
+++ b/README.md
@@ -66,6 +66,10 @@ Normalizers for [periodic](https://en.wikipedia.org/wiki/Periodic_function) sign
 
 [atan](https://en.wikipedia.org/wiki/Inverse_trigonometric_functions) and [atan2](https://en.wikipedia.org/wiki/Atan2).
 
+### [exp.hh](exp.hh)
+
+[Exponentiation](https://en.wikipedia.org/wiki/Exponentiation) approximations.
+
 ### [cordic.hh](cordic.hh)
 
 When working on a device where multiplication is expensive, the [CORDIC](https://en.wikipedia.org/wiki/CORDIC) comes in handy for computing [trigonometric functions](https://en.wikipedia.org/wiki/Trigonometric_functions).
diff --git a/exp.hh b/exp.hh
new file mode 100644
index 0000000..6e822a4
--- /dev/null
+++ b/exp.hh
@@ -0,0 +1,53 @@
+/*
+Exponentiation approximations
+
+Constants below lifted from the Cephes Mathematical Library:
+https://www.netlib.org/cephes/cmath.tgz
+
+Copyright 2018 Ahmet Inan <inan@aicodix.de>
+*/
+
+#pragma once
+
+namespace DSP {
+
+template <typename TYPE>
+TYPE ldexp(TYPE x, int n)
+{
+	int a = n < 0 ? -n : n;
+	int a8 = a / 8;
+	int ar = a - a8 * 8;
+	TYPE t = 1 << a8;
+	t *= t;
+	t *= t;
+	t *= t;
+	t *= 1 << ar;
+	return n < 0 ? x / t : x * t;
+}
+
+template <typename TYPE>
+TYPE exp10(TYPE x)
+{
+	static constexpr TYPE
+		LOG210 = 3.32192809488736234787e0,
+		LG102A = 3.01025390625000000000E-1,
+		LG102B = 4.60503898119521373889E-6,
+		P0 = 4.09962519798587023075E-2,
+		P1 = 1.17452732554344059015E1,
+		P2 = 4.06717289936872725516E2,
+		P3 = 2.39423741207388267439E3,
+		Q0 = 8.50936160849306532625E1,
+		Q1 = 1.27209271178345121210E3,
+		Q2 = 2.07960819286001865907E3;
+	TYPE i = nearbyint(x * LOG210);
+	x -= i * LG102A;
+	x -= i * LG102B;
+	TYPE xx = x * x;
+	TYPE py = x * (xx * (xx * (xx * P0 + P1) + P2) + P3);
+	TYPE qy = xx * (xx * (xx + Q0) + Q1) + Q2;
+	TYPE pq = TYPE(1) + TYPE(2) * py / (qy - py);
+	return ldexp(pq, (int)i);
+}
+
+}
+