It measures 8.5 by 11 inches (215.9 by 279.4 mm), which is equivalent to the A4 paper standard used in most other nations, as established by the International Organization for Standardization in ISO 216. The term "letter" comes from the fact that these pages were originally printed on woodblocks with hand-cut holes for the typeface to go through; before that, letters were hand drawn and engraved by printers who needed a common size to fit their books.

The word "inch" comes from the Latin for "thousand," because 1 inch is 0.0254 cm. But the term is also used to indicate the length of a finger, so it can also be said that an "inch" is 0.0254 m. This is important to remember when measuring with hands or fingers: 0.0254 cm and 0.0254 m are not the same thing!

The term "metric system" refers to systems of measurements based on the metric unit of measure, the meter. The English system is based on the unit called the "foot", which is 0.3048 m long, but this term isn't used anymore except in sports or military contexts. Everything is measured in meters now, including the kilometer, which is 1000 meters, and the mile, which is 0.6213 km.

The International Standard Paper Sizes A-Series

Size | Other Names | Width x Height (in) |
---|---|---|

A4 | Letter | 8.3” x 11.7” |

A5 | (-) | 5.8” × 8.3” |

A6 | (-) | 4.1” × 5.8” |

A7 | (-) | 2.9” × 4.1” |

Paper Size Chart

Size Name | Size in mm (without bleed area) | Size in mm (with bleed area) |
---|---|---|

A6 | 148 x 105 mm | 154 x 111 mm |

A5 | 210 x 148 mm | 216 x 154 mm |

A4 | 297 x 210 mm | 303 x 216 mm |

A3 | 420 x 297 mm | 426 x 303 mm |

This estimate assists other scientists in determining the precision with which the measurement was done. Every measurement has **an approximate value**. The digit before the estimate is invariably a device mark. The markings on the ruler above are every 0.1 cm or 1 mm. Thus, this measurement was probably within 0.1 cm of 3.9 inches.

The first number after the decimal point indicates the number of digits after the decimal point. So, in **this case**, there are about three digits of accuracy in the measurement.

When you read that a measurement is accurate to five digits, that means the measurement could be anywhere from 3.9 inches to 4.1 inches. Five digits of accuracy would mean that the measurement could be off by **as much as 0.1 inch**.

In general, one can say that a measurement is accurate to x digits if when repeated exactly, the result falls within x times the range of the measurement. For example, if the measurement taken using the scale is 39 inches and it is known to be accurate to **five digits**, then the actual length cannot be more than 4.9 feet or less than 3.9 feet.

Digits after the decimal point indicate the number of digits after the decimal point for which the measurement is accurate.

Only ordinary letter-size paper should be used (8" x 10"). If you use 11" x 14" paper, you will need to reduce the ink by half. For **best results**, print on both sides of the page.

It must have the dimensions length x **width x height**. That is the industry standard for measures. It makes **no difference** the order you list them in. Length, width and height all need to be measured to the nearest inch.

For example: A panel that is 72 inches by **54 inches** by 3/4 inch thick is called a "speaker cabinet". The term "cabinet" is used instead of "panel" if it's made of wood. The word "screen" is also used instead of "panel" if it's made of metal or plastic.

The term "room" is usually reserved for spaces that aren't specifically sized like feet or meters. For example: "We rented a room at the inn." "The shop has been able to rent out its upstairs space."

Measurements can also be listed as maximum sizes. For example: "The bed needs to be 60 inches wide." Or they may be listed in ratios. For example: "The couch can be as long as there's room." Or they may simply state an overall size with no specific measurement given, like this: "A speaker cabinet uses panels cut to fit their shape."

Overall size is usually given in feet and inches, such as **12 feet** by 14 feet.

Specifications | Type | Size (mm) |
---|---|---|

Capital letter height | A | 3.5 |

B | 3.5 | |

Lowercase letter height | A | 2.5 |

B | 2.5 |

The SAE-to-Metric Conversion Table

SAE | Metric | Inch |
---|---|---|

9mm | 0.354 | |

3/8″ | 0.375 | |

10mm | 0.394 | |

13/32″ | 0.406 |