# Data Type Storage Requirements
The following tables indicate the approximate data storage requirements for each data type.
## Numeric Data Types
| Data Type | Storage Requirement |
| ---------------------------------------------------------------------------------------------- | ------------------------------------- |
| [TINYINT](https://mariadb.com/docs/server/reference/data-types/numeric-data-types/tinyint) | 1 byte |
| [SMALLINT](https://mariadb.com/docs/server/reference/data-types/numeric-data-types/smallint) | 2 bytes |
| [MEDIUMINT](https://mariadb.com/docs/server/reference/data-types/numeric-data-types/mediumint) | 3 bytes |
| [INT](https://mariadb.com/docs/server/reference/data-types/numeric-data-types/int) | 4 bytes |
| [BIGINT](https://mariadb.com/docs/server/reference/data-types/numeric-data-types/bigint) | 8 bytes |
| [FLOAT](https://mariadb.com/docs/server/reference/data-types/numeric-data-types/float)(p) | 4 bytes if p <= 24, otherwise 8 bytes |
| [DOUBLE](https://mariadb.com/docs/server/reference/data-types/numeric-data-types/double) | 8 bytes |
| [DECIMAL](https://mariadb.com/docs/server/reference/data-types/numeric-data-types/decimal) | See table below |
| [BIT](https://mariadb.com/docs/server/reference/data-types/numeric-data-types/bit)(M) | (M+7)/8 bytes |
Note that `MEDIUMINT` columns will require 4 bytes in memory (for example, in InnoDB buffer pool).
### Decimal
[Decimals](https://mariadb.com/docs/server/reference/data-types/numeric-data-types/decimal) are stored using a binary format, with the integer and the fraction stored separately. Each nine-digit multiple requires 4 bytes, followed by a number of bytes for whatever remains, as follows:
| Remaining digits | Storage Requirement |
| ---------------- | ------------------- |
| 0 | 0 bytes |
| 1 | 1 byte |
| 2 | 1 byte |
| 3 | 2 bytes |
| 4 | 2 bytes |
| 5 | 3 bytes |
| 6 | 3 bytes |
| 7 | 4 bytes |
| 8 | 4 bytes |
## String Data Types
In the descriptions below, `M` is the declared column length (in characters or in bytes), while `len` is the actual length in bytes of the value.
| Data Type | Storage Requirement |
| ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | ---------------------------------------------------------------------------------------------------------- |
| [ENUM](https://mariadb.com/docs/server/reference/data-types/string-data-types/enum) | 1 byte for up to 255 enum values, 2 bytes for 256 to 65,535 enum values |
| [CHAR(M)](https://mariadb.com/docs/server/reference/data-types/string-data-types/char) | M × w bytes, where w is the number of bytes required for the maximum-length character in the character set |
| [BINARY(M)](https://mariadb.com/docs/server/reference/data-types/string-data-types/binary) | M bytes |
| [VARCHAR(M)](https://mariadb.com/docs/server/reference/data-types/string-data-types/varchar), [VARBINARY(M)](https://mariadb.com/docs/server/reference/data-types/string-data-types/varbinary) | len + 1 bytes if column is 0 – 255 bytes, len + 2 bytes if column may require more than 255 bytes |
| [TINYBLOB](https://mariadb.com/docs/server/reference/data-types/string-data-types/tinyblob), [TINYTEXT](https://mariadb.com/docs/server/reference/data-types/string-data-types/tinytext) | len + 1 bytes |
| [BLOB](https://mariadb.com/docs/server/reference/data-types/string-data-types/blob), [TEXT](https://mariadb.com/docs/server/reference/data-types/string-data-types/text) | len + 2 bytes |
| [MEDIUMBLOB](https://mariadb.com/docs/server/reference/data-types/string-data-types/mediumblob), [MEDIUMTEXT](https://mariadb.com/docs/server/reference/data-types/string-data-types/mediumtext) | len + 3 bytes |
| [LONGBLOB](https://mariadb.com/docs/server/reference/data-types/string-data-types/longblob), [LONGTEXT](https://mariadb.com/docs/server/reference/data-types/string-data-types/longtext) | len + 4 bytes |
| [XMLTYPE](https://mariadb.com/docs/server/reference/data-types/string-data-types/xmltype) | len + 4 bytes (same as LONGBLOB) |
| [SET](https://mariadb.com/docs/server/reference/data-types/string-data-types/set-data-type) | Given M members of the set, (M+7)/8 bytes, rounded up to 1, 2, 3, 4, or 8 bytes |
| [INET6](https://mariadb.com/docs/server/reference/data-types/string-data-types/inet6) | 16 bytes |
| [UUID](https://mariadb.com/docs/server/reference/data-types/string-data-types/uuid-data-type) | 16 bytes |
**Note**: Introduced in MariaDB 12.3, the `XMLTYPE` data type has a maximum storage capacity of 4GB, similar to `LONGBLOB`*.*
In some [character sets](https://mariadb.com/docs/server/reference/data-types/string-data-types/character-sets), not all characters use the same number of bytes. utf8 encodes characters with one to three bytes per character, while `utf8mb4` requires one to four bytes per character.
When using field the `COMPRESSED` attribute, 1 byte is reserved for metadata. For example, `VARCHAR(255)` will use +2 bytes instead of +1.
### Examples
Assuming a single-byte character-set:
| Value | CHAR(2) | Storage Required | VARCHAR(2) | Storage Required |
| ----- | ------- | ---------------- | ---------- | ---------------- |
| '' | ' ' | 2 bytes | '' | 1 byte |
| '1' | '1 ' | 2 bytes | '1' | 2 bytes |
| '12' | '12' | 2 bytes | '12' | 3 bytes |
## Date and Time Data Types
| Data Type | Storage Requirement |
| ---------------------------------------------------------------------------------------------------- | ------------------- |
| [DATE](https://mariadb.com/docs/server/reference/data-types/date-and-time-data-types/date) | 3 bytes |
| [TIME](https://mariadb.com/docs/server/reference/data-types/date-and-time-data-types/time) | 3 bytes |
| [DATETIME](https://mariadb.com/docs/server/reference/data-types/date-and-time-data-types/datetime) | 8 bytes |
| [TIMESTAMP](https://mariadb.com/docs/server/reference/data-types/date-and-time-data-types/timestamp) | 4 bytes |
| [YEAR](https://mariadb.com/docs/server/reference/data-types/date-and-time-data-types/year-data-type) | 1 byte |
### Microseconds
MariaDB defaults to the MySQL format (by means of the [mysql56\_temporal\_format](https://mariadb.com/docs/server/server-management/variables-and-modes/server-system-variables#mysql56_temporal_format) variable). Microseconds have the following additional storage requirements:
| Precision | Storage Requirement |
| --------- | ------------------- |
| 0 | 0 bytes |
| 1,2 | 1 byte |
| 3,4 | 2 bytes |
| 5,6 | 3 bytes |
## NULL Values
For the InnoDB [COMPACT](https://mariadb.com/docs/server/server-usage/storage-engines/innodb/innodb-row-formats/innodb-compact-row-format), [DYNAMIC](https://mariadb.com/docs/server/server-usage/storage-engines/innodb/innodb-row-formats/innodb-dynamic-row-format) and [COMPRESSED](https://mariadb.com/docs/server/server-usage/storage-engines/innodb/innodb-row-formats/innodb-compressed-row-format) row formats, a number of bytes will be allocated in the record header for the nullable fields. If there are between 1 and 8 nullable fields, 1 such byte will be allocated. In the record payload area, no space will be reserved for values that are `NULL`.
For the [InnoDB REDUNDANT row format](https://mariadb.com/docs/server/server-usage/storage-engines/innodb/innodb-row-formats/innodb-redundant-row-format), the overhead is 1 bit in the record header (as a part of the 1-byte or 2-byte "end of field" pointer). In that format, a `NULL` fixed-length field will consume the same amount of space as any `NOT NULL` value in the record payload area. The motivation is that it is possible to update in place between `NOT NULL` and `NULL` values.
In other formats, `NULL` values usually require 1 bit in the data file, 1 byte in the index file.
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