diff --git a/stl/inc/format b/stl/inc/format
index addbe13cdf7..a94aa8f8496 100644
--- a/stl/inc/format
+++ b/stl/inc/format
@@ -46,6 +46,11 @@ concept _Parse_spec_callbacks = requires(_Ty _At, basic_string_view<_CharT> _Sv,
     { _At._On_width(_STD declval<int>()) } -> same_as<void>;
     { _At._On_dynamic_width(_STD declval<int>()) } -> same_as<void>;
     { _At._On_dynamic_width(_STD declval<_Auto_id_tag>()) } -> same_as<void>;
+    { _At._On_precision(_STD declval<int>()) } -> same_as<void>;
+    { _At._On_dynamic_precision(_STD declval<int>()) } -> same_as<void>;
+    { _At._On_dynamic_precision(_STD declval<_Auto_id_tag>()) } -> same_as<void>;
+
+    /* { _At._On_type(_STD declval<_CharT>()) } -> same_as<void>; */
 };
 template <class _Ty, class _CharT>
 concept _Parse_arg_id_callbacks = requires(_Ty _At) {
@@ -86,6 +91,7 @@ constexpr const _CharT* _Parse_arg_id(const _CharT* _Begin, const _CharT* _End,
         _Callbacks._On_auto_id();
         return _Begin;
     }
+
     if (_Ch >= '0' && _Ch <= '9') {
         int _Index = 0;
         // arg_id is not allowed to have any leading zeros, but is allowed to be
@@ -161,7 +167,7 @@ template <class _CharT, _Parse_spec_callbacks<_CharT> _Callbacks_type>
 struct _Width_adapter {
     _Callbacks_type& _Callbacks;
 
-    explicit constexpr _Width_adapter(_Callbacks_type& _Handler) : _Callbacks(_Handler) {}
+    constexpr explicit _Width_adapter(_Callbacks_type& _Handler) : _Callbacks(_Handler) {}
 
     constexpr void _On_auto_id() {
         _Callbacks._On_dynamic_width(_Auto_id_tag{});
@@ -171,6 +177,22 @@ struct _Width_adapter {
     }
 };
 
+// Adapts a type modeling _Parse_spec_callbacks to model _Parse_arg_id_callbacks.
+// Used in _Parse_precision so that _Parse_arg_id can be used to parse dynamic precisions.
+template <class _CharT, _Parse_spec_callbacks<_CharT> _Callbacks_type>
+struct _Precision_adapter {
+    _Callbacks_type& _Callbacks;
+
+    constexpr explicit _Precision_adapter(_Callbacks_type& _Handler) : _Callbacks(_Handler) {}
+
+    constexpr void _On_auto_id() {
+        _Callbacks._On_dynamic_precision(_Auto_id_tag{});
+    }
+    constexpr void _On_manual_id(int _Id) {
+        _Callbacks._On_dynamic_precision(_Id);
+    }
+};
+
 template <class _CharT, _Parse_spec_callbacks<_CharT> _Callbacks_type>
 constexpr const _CharT* _Parse_width(const _CharT* _Begin, const _CharT* _End, _Callbacks_type&& _Callbacks) {
     _STL_INTERNAL_CHECK(_Begin != _End);
@@ -181,7 +203,7 @@ constexpr const _CharT* _Parse_width(const _CharT* _Begin, const _CharT* _End, _
     } else if (*_Begin == '{') {
         ++_Begin;
         if (_Begin != _End) {
-            _Begin = _Parse_arg_id(_Begin, _End, _Width_adapter<_CharT, _Callbacks_type>(_Callbacks));
+            _Begin = _Parse_arg_id(_Begin, _End, _Width_adapter<_CharT, _Callbacks_type>{_Callbacks});
         }
         if (_Begin == _End || *_Begin != '}') {
             throw format_error("Invalid format string.");
@@ -191,6 +213,33 @@ constexpr const _CharT* _Parse_width(const _CharT* _Begin, const _CharT* _End, _
     return _Begin;
 }
 
+template <class _CharT, _Parse_spec_callbacks<_CharT> _Callbacks_type>
+constexpr const _CharT* _Parse_precision(const _CharT* _Begin, const _CharT* _End, _Callbacks_type&& _Callbacks) {
+    ++_Begin;
+    _CharT _Ch = '\0';
+    if (_Begin != _End) {
+        _Ch = *_Begin;
+    }
+
+    if ('0' <= _Ch && _Ch <= '9') {
+        int _Precision = 0;
+        _Begin         = _Parse_nonnegative_integer(_Begin, _End, _Precision);
+        _Callbacks._On_precision(_Precision);
+    } else if (_Ch == '{') {
+        ++_Begin;
+        if (_Begin != _End) {
+            _Begin = _Parse_arg_id(_Begin, _End, _Precision_adapter<_CharT, _Callbacks_type>{_Callbacks});
+        }
+
+        if (_Begin == _End || *_Begin != '}') {
+            throw format_error("Invalid format string.");
+        }
+    } else {
+        throw format_error("Missing precision specifier.");
+    }
+    return _Begin;
+}
+
 template <class _Ty, class _CharT = char>
 struct formatter;
 
diff --git a/tests/std/tests/P0645R10_text_formatting_parsing/test.cpp b/tests/std/tests/P0645R10_text_formatting_parsing/test.cpp
index 89aec01765a..187dca249b5 100644
--- a/tests/std/tests/P0645R10_text_formatting_parsing/test.cpp
+++ b/tests/std/tests/P0645R10_text_formatting_parsing/test.cpp
@@ -33,9 +33,12 @@ template <typename CharT>
 struct testing_callbacks {
     _Align expected_alignment = _Align::_None;
     basic_string_view<CharT> expected_fill;
-    int expected_width               = -1;
-    int expected_dynamic_width       = -1;
-    bool expected_auto_dynamic_width = false;
+    int expected_width                   = -1;
+    int expected_dynamic_width           = -1;
+    bool expected_auto_dynamic_width     = false;
+    int expected_precision               = -1;
+    int expected_dynamic_precision       = -1;
+    bool expected_auto_dynamic_precision = false;
     constexpr void _On_align(_Align aln) {
         assert(aln == expected_alignment);
     }
@@ -51,6 +54,15 @@ struct testing_callbacks {
     constexpr void _On_dynamic_width(_Auto_id_tag) {
         assert(expected_auto_dynamic_width);
     }
+    constexpr void _On_precision(int pre) {
+        assert(pre == expected_precision);
+    }
+    constexpr void _On_dynamic_precision(int id) {
+        assert(id == expected_dynamic_precision);
+    }
+    constexpr void _On_dynamic_precision(_Auto_id_tag) {
+        assert(expected_auto_dynamic_precision);
+    }
 };
 template <typename CharT>
 testing_callbacks(_Align, basic_string_view<CharT>) -> testing_callbacks<CharT>;
@@ -81,10 +93,10 @@ constexpr bool test_parse_align() {
     auto parse_align_fn = _Parse_align<CharT, testing_callbacks<CharT>>;
     using view_typ      = basic_string_view<CharT>;
 
-    auto s0 = view_typ(TYPED_LITERAL(CharT, ""));
-    auto s1 = view_typ(TYPED_LITERAL(CharT, "*<"));
-    auto s2 = view_typ(TYPED_LITERAL(CharT, "*>"));
-    auto s3 = view_typ(TYPED_LITERAL(CharT, "*^"));
+    view_typ s0(TYPED_LITERAL(CharT, ""));
+    view_typ s1(TYPED_LITERAL(CharT, "*<"));
+    view_typ s2(TYPED_LITERAL(CharT, "*>"));
+    view_typ s3(TYPED_LITERAL(CharT, "*^"));
 
     test_parse_helper(parse_align_fn, s0, false, view_typ::npos, {_Align::_None, view_typ(TYPED_LITERAL(CharT, ""))});
     test_parse_helper(parse_align_fn, s1, false, view_typ::npos, {_Align::_Left, view_typ(TYPED_LITERAL(CharT, "*"))});
@@ -108,12 +120,12 @@ constexpr bool test_parse_width() {
     auto parse_width_fn = _Parse_width<CharT, testing_callbacks<CharT>>;
     using view_typ      = basic_string_view<CharT>;
 
-    auto s0 = view_typ(TYPED_LITERAL(CharT, "1"));
-    auto s1 = view_typ(TYPED_LITERAL(CharT, "{1}"));
-    auto s2 = view_typ(TYPED_LITERAL(CharT, "{0}"));
-    auto s3 = view_typ(TYPED_LITERAL(CharT, "{}"));
-    auto i0 = view_typ(TYPED_LITERAL(CharT, "0"));
-    auto i1 = view_typ(TYPED_LITERAL(CharT, "01"));
+    view_typ s0(TYPED_LITERAL(CharT, "1"));
+    view_typ s1(TYPED_LITERAL(CharT, "{1}"));
+    view_typ s2(TYPED_LITERAL(CharT, "{0}"));
+    view_typ s3(TYPED_LITERAL(CharT, "{}"));
+    view_typ i0(TYPED_LITERAL(CharT, "0"));
+    view_typ i1(TYPED_LITERAL(CharT, "01"));
 
     test_parse_helper(parse_width_fn, s0, false, view_typ::npos, {.expected_width = 1});
     test_parse_helper(parse_width_fn, s1, false, view_typ::npos, {.expected_dynamic_width = 1});
@@ -130,14 +142,14 @@ constexpr bool test_parse_arg_id() {
     using view_typ       = basic_string_view<CharT>;
     // note that parse arg id starts with the arg id itself, not the { beginning of the
     // format spec
-    auto s0 = view_typ(TYPED_LITERAL(CharT, "}"));
-    auto s1 = view_typ(TYPED_LITERAL(CharT, ":"));
-    auto s2 = view_typ(TYPED_LITERAL(CharT, ":}"));
-    auto s3 = view_typ(TYPED_LITERAL(CharT, "0:}"));
-    auto s4 = view_typ(TYPED_LITERAL(CharT, "0:"));
-    auto s5 = view_typ(TYPED_LITERAL(CharT, "1}"));
-    auto i0 = view_typ(TYPED_LITERAL(CharT, "01}"));
-    auto i1 = view_typ(TYPED_LITERAL(CharT, "0"));
+    view_typ s0(TYPED_LITERAL(CharT, "}"));
+    view_typ s1(TYPED_LITERAL(CharT, ":"));
+    view_typ s2(TYPED_LITERAL(CharT, ":}"));
+    view_typ s3(TYPED_LITERAL(CharT, "0:}"));
+    view_typ s4(TYPED_LITERAL(CharT, "0:"));
+    view_typ s5(TYPED_LITERAL(CharT, "1}"));
+    view_typ i0(TYPED_LITERAL(CharT, "01}"));
+    view_typ i1(TYPED_LITERAL(CharT, "0"));
 
     test_parse_helper(parse_arg_id_fn, s0, false, 0);
     test_parse_helper(parse_arg_id_fn, s1, false, 0);
@@ -156,6 +168,38 @@ constexpr bool test_parse_arg_id() {
     return true;
 }
 
+template <typename CharT>
+constexpr bool test_parse_precision() {
+    auto parse_pre_fn = _Parse_precision<CharT, testing_callbacks<CharT>>;
+    using view_typ    = basic_string_view<CharT>;
+
+    view_typ s0(TYPED_LITERAL(CharT, ".0"));
+    view_typ s1(TYPED_LITERAL(CharT, ".1"));
+    view_typ s2(TYPED_LITERAL(CharT, ".12"));
+    view_typ s3(TYPED_LITERAL(CharT, ".{1}"));
+    view_typ s4(TYPED_LITERAL(CharT, ".{}"));
+
+    view_typ i0(TYPED_LITERAL(CharT, ".{ }"));
+    view_typ i1(TYPED_LITERAL(CharT, "."));
+    view_typ i2(TYPED_LITERAL(CharT, ".{    |"));
+    view_typ i3(TYPED_LITERAL(CharT, ".{"));
+
+    test_parse_helper(parse_pre_fn, s0, false, view_typ::npos, {.expected_precision = 0});
+    test_parse_helper(parse_pre_fn, s1, false, view_typ::npos, {.expected_precision = 1});
+    test_parse_helper(parse_pre_fn, s2, false, view_typ::npos, {.expected_precision = 12});
+    test_parse_helper(parse_pre_fn, s3, false, view_typ::npos, {.expected_dynamic_precision = 1});
+    test_parse_helper(parse_pre_fn, s4, false, view_typ::npos, {.expected_auto_dynamic_precision = true});
+
+    if (!is_constant_evaluated()) {
+        test_parse_helper(parse_pre_fn, i0, true);
+        test_parse_helper(parse_pre_fn, i1, true);
+        test_parse_helper(parse_pre_fn, i2, true);
+        test_parse_helper(parse_pre_fn, i3, true);
+    }
+
+    return true;
+}
+
 int main() {
     test_parse_align<char>();
     test_parse_align<wchar_t>();
@@ -169,5 +213,9 @@ int main() {
     test_parse_width<wchar_t>();
     static_assert(test_parse_width<char>());
     static_assert(test_parse_width<wchar_t>());
+    test_parse_precision<char>();
+    test_parse_precision<wchar_t>();
+    static_assert(test_parse_precision<char>());
+    static_assert(test_parse_precision<wchar_t>());
     return 0;
 }