diff -r 3a880d640981 Lib/decimal.py
--- a/Lib/decimal.py	Tue Sep 18 07:21:18 2012 +0300
+++ b/Lib/decimal.py	Tue Sep 18 09:49:58 2012 +0200
@@ -6050,6 +6050,21 @@
 
 ##### Setup Specific Contexts ############################################
 
+class IEEEContext(Context):
+    """Return the decimal<n> IEEE 754 context.
+    n should be a multiple of 32."""
+    def __init__(self, n):
+         assert n >= 32 and n % 32 == 0
+
+         prec = 9 * n//32 - 2
+         Emax = 3 * 2**(n//16 + 3)
+
+         super(IEEEContext, self).__init__(
+                 prec=prec,
+                 Emax=Emax,
+         )
+
+
 # The default context prototype used by Context()
 # Is mutable, so that new contexts can have different default values
 
diff -r 3a880d640981 Lib/test/test_decimal.py
--- a/Lib/test/test_decimal.py	Tue Sep 18 07:21:18 2012 +0300
+++ b/Lib/test/test_decimal.py	Tue Sep 18 09:49:58 2012 +0200
@@ -3644,6 +3644,18 @@
 class PySpecialContexts(SpecialContexts):
     decimal = P
 
+class TestIEEEContext(unittest.TestCase):
+
+    def test_precision(self):
+        decimal32 = self.decimal.IEEEContext(32)
+        decimal64 = self.decimal.IEEEContext(64)
+        decimal128 = self.decimal.IEEEContext(128)
+        decimal256 = self.decimal.IEEEContext(256)
+
+        # example ieee754, section 3.6
+        self.assertEquals(decimal256.prec, 70)
+        self.assertEquals(decimal256.Emax, 1572864)
+
 class ContextInputValidation(unittest.TestCase):
 
     def test_invalid_context(self):