diff --git a/sprout/integer/integer_digits.hpp b/sprout/integer/integer_digits.hpp
new file mode 100644
index 00000000..e23b8349
--- /dev/null
+++ b/sprout/integer/integer_digits.hpp
@@ -0,0 +1,92 @@
+#ifndef SPROUT_INTEGER_INTEGER_DIGITS_HPP
+#define SPROUT_INTEGER_INTEGER_DIGITS_HPP
+
+#include <cstddef>
+#include <climits>
+#include <type_traits>
+#include <sprout/config.hpp>
+
+namespace sprout {
+	namespace detail {
+		//
+		// integer_digits_impl
+		//
+		template<typename IntType, long N, long D>
+		struct integer_digits_impl
+			: public std::integral_constant<
+				std::size_t,
+				(CHAR_BIT * sizeof(IntType) - (std::is_signed<IntType>::value ? 1 : 0)) * N / D
+				+ ((CHAR_BIT * sizeof(IntType) - (std::is_signed<IntType>::value ? 1 : 0)) * N % D ? 1 : 0)
+			>
+		{};
+	}	// namespace detail
+
+	//
+	// integer_digits
+	//
+	template<typename IntType, std::size_t Base>
+	struct integer_digits;
+
+	template<typename IntType>
+	struct integer_digits<IntType, 2>
+		: public sprout::detail::integer_digits_impl<IntType, 1, 1>
+	{};
+	template<typename IntType>
+	struct integer_digits<IntType, 3>
+		: public sprout::detail::integer_digits_impl<IntType, 630, 1000>
+	{};
+	template<typename IntType>
+	struct integer_digits<IntType, 4>
+		: public sprout::detail::integer_digits_impl<IntType, 1, 2>
+	{};
+	template<typename IntType>
+	struct integer_digits<IntType, 5>
+		: public sprout::detail::integer_digits_impl<IntType, 430, 1000>
+	{};
+	template<typename IntType>
+	struct integer_digits<IntType, 6>
+		: public sprout::detail::integer_digits_impl<IntType, 386, 1000>
+	{};
+	template<typename IntType>
+	struct integer_digits<IntType, 7>
+		: public sprout::detail::integer_digits_impl<IntType, 356, 1000>
+	{};
+	template<typename IntType>
+	struct integer_digits<IntType, 8>
+		: public sprout::detail::integer_digits_impl<IntType, 1, 3>
+	{};
+	template<typename IntType>
+	struct integer_digits<IntType, 9>
+		: public sprout::detail::integer_digits_impl<IntType, 315, 1000>
+	{};
+	template<typename IntType>
+	struct integer_digits<IntType, 10>
+		: public sprout::detail::integer_digits_impl<IntType, 301, 1000>
+	{};
+	template<typename IntType>
+	struct integer_digits<IntType, 11>
+		: public sprout::detail::integer_digits_impl<IntType, 289, 1000>
+	{};
+	template<typename IntType>
+	struct integer_digits<IntType, 12>
+		: public sprout::detail::integer_digits_impl<IntType, 278, 1000>
+	{};
+	template<typename IntType>
+	struct integer_digits<IntType, 13>
+		: public sprout::detail::integer_digits_impl<IntType, 270, 1000>
+	{};
+	template<typename IntType>
+	struct integer_digits<IntType, 14>
+		: public sprout::detail::integer_digits_impl<IntType, 262, 1000>
+	{};
+	template<typename IntType>
+	struct integer_digits<IntType, 15>
+		: public sprout::detail::integer_digits_impl<IntType, 255, 1000>
+	{};
+	template<typename IntType>
+	struct integer_digits<IntType, 16>
+		: public sprout::detail::integer_digits_impl<IntType, 1, 4>
+	{};
+}	// namespace sprout
+
+#endif	// #ifndef SPROUT_INTEGER_INTEGER_DIGITS_HPP