Conversion Table: Surrogates to Scalar Value/UTF-32

The converter table (the second table) on this page can be used to convert pairs of Unicode surrogate code points to Unicode scalar values (equivalent to UTF-32 values). Surrogate code points are the values in UTF-16 encoding of the two 16-bit code units that make up a Supplementary Character. The conversion of these two values to the single Unicode scalar value gives you the numerical identifier for the character, a value in the range of 10000 to 10FFFF for supplementary characters. (Usually expressed in the form U+10000 to U+10FFFF.) The Unicode scalar values are also the code unit values the character would have in UTF-32.

Using the Surrogates to Scalar Value/UTF-32 Conversion Table

The leftmost column of the conversion table contains high surrogate values. Choose the row with the value matching the high surrogate that you want to convert. The remaining columns identify ranges of low surrogate values. The ranges go from 00-FF (0-255). Choose the pair of columns which contains the low surrogate value you want to convert. looking down to the intersection of the high and low surrogate values you can read off the associated range of Unicode scalar values. Use interpolation to identify the particular scalar value between 00-FF, that corresponds to the particular low surrogate you are converting from.

For example, to convert D803 DD75, look at row D803 and across to the columns DD00-DDFF. This gives you the scalar values 10D00-10DFF. The value for D803 DD75 is therefore 10D75.

The table immediately below is a jump table for high surrogate values. Click on the high surrogate and the page will jump to that row in the second table. In the second table, clicking on any high surrogate value returns you to the top of the page.

You can of course also go in the opposite direction, by searching the table for scalar value ranges and then the row and column headings determine the surrogate values.

More information on surrogate coded points can be found in Chapter 3.7 of the Unicode Standard.
The Unicode Consortium also has a Frequently Asked Questions (FAQ) page on UTF & BOM which discusses surrogates.
If you are using Microsoft Windows, see Setting up Windows NT or Windows 2000 or Windows XP to support Unicode supplementary characters.

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