Here is a script which list out all the identity columns and percentage used
SET NOCOUNT ONSELECT SCHEMA_NAME(t.schema_id) + '.' + t.name AS TableName,idc.name AS ColumnName,CASE idc.system_type_idWHEN 127 THEN 'bigint'WHEN 56 THEN 'int'WHEN 52 THEN 'smallint'WHEN 48 THEN 'tinyint'END AS 'DataType',idc.last_value AS CurrentIdentityValue,idc.seed_value,increment_value,CASE idc.system_type_idWHEN 127 THEN ((CONVERT(INT, idc.last_value) - CONVERT(INT, idc.seed_value) )+1 )* 100. / 9223372036854775806/CONVERT(INT,increment_value)WHEN 56 THEN ((CONVERT(INT, idc.last_value)- CONVERT(INT, idc.seed_value) )+1 )* 100. / 2147483646/CONVERT(INT,increment_value)WHEN 52 THEN ((CONVERT(INT, idc.last_value)- CONVERT(INT, idc.seed_value) )+1 )* 100. / 32766/CONVERT(INT,increment_value)WHEN 48 THEN ((CONVERT(INT, idc.last_value)- CONVERT(INT, idc.seed_value) )+1 ) * 100. / 256/CONVERT(INT,increment_value)END AS 'PercentageUsed'FROM sys.tables AS tINNER JOIN sys.identity_columns idc ON idc.object_id = t.object_idWHERE idc.is_identity = 1ORDER BY PercentageUsed DESC