Archived reference library
Find a length you can picture.
105 references: 97 sourced objects and 8 exact units. Explore definitions, sources and comparisons.
5,460 unordered conversion pairs, excluding self-pairs. Choose any two references to compare their defined lengths.
This preserves the 2026-10-19 catalogue. Browse current references.
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Browse 16 categories
Metric
4 referenceslength
Exact unit definition
1 mm
length
Exact unit definition
1 cm
length
Exact unit definition
1 m
length
Exact unit definition
1 km
US customary / imperial
4 referenceslength
Exact unit definition
1 in
length
Exact unit definition
1 ft
length
Exact unit definition
1 yd
length
Exact unit definition
1 mi
Everyday objects
5 referenceslong edge
Nominal standard size
≈ 85.60 mm
long edge
Nominal standard size
≈ 297 mm
long edge
Published reference measurement
≈ 6.14 in
brick length excluding mortar
Nominal standard size
≈ 215 mm
nominal disc diameter
Nominal standard size
≈ 120 mm
Coins
7 referencesdiameter
Manufacturer specification
≈ 24.26 mm
diameter
Nominal standard size
≈ 0.75 in
diameter
Nominal standard size
≈ 0.835 in
diameter
Nominal standard size
≈ 0.705 in
diameter
Nominal standard size
≈ 1.205 in
diameter
Nominal standard size
≈ 1.043 in
diameter
Nominal standard size
≈ 23.25 mm
Fruits
6 referencesdiameter
Documented sample mean
≈ 7.63 cm
fruit diameter
Chosen midpoint of a documented range
≈ 1.25 in
fruit length
Chosen midpoint of a documented range
≈ 4 in
fruit diameter
Chosen midpoint of a documented range
≈ 5.75 cm
fruit diameter
Chosen midpoint of a documented range
≈ 1.375 in
fruit length blossom to stem
Published reference measurement
≈ 42.5 mm
Vegetables
7 referencesroot length, without foliage
Chosen midpoint of a documented range
≈ 6.5 in
harvest fruit length
Chosen midpoint of a documented range
≈ 6.5 in
fruit length
Chosen midpoint of a documented range
≈ 8 in
harvest fruit length
Chosen midpoint of a documented range
≈ 7 in
harvest pod length
Chosen midpoint of a documented range
≈ 3 in
harvest root diameter
Chosen midpoint of a documented range
≈ 2 in
harvest root diameter
Published reference measurement
≈ 1 in
Toys
9 referencesassembled model length
Rounded manufacturer reference
≈ 84 cm
assembled model height
Rounded manufacturer reference
≈ 149 cm
assembled model length
Rounded manufacturer reference
≈ 135 cm
assembled model height
Rounded manufacturer reference
≈ 18 cm
assembled model width
Rounded manufacturer reference
≈ 30.5 cm
assembled model height
Rounded manufacturer reference
≈ 40 cm
assembled model width
Rounded manufacturer reference
≈ 27 cm
assembled model length
Rounded manufacturer reference
≈ 105 cm
assembled model height
Rounded manufacturer reference
≈ 80 cm
Sports
6 referencesdiameter
Nominal standard size
≈ 40 mm
playing-surface length
Nominal standard size
≈ 2.74 m
pitch length
Nominal standard size
≈ 22 yd
inside ring diameter
Nominal standard size
≈ 18 in
backboard width
Nominal standard size
≈ 6 ft
field length including end zones
Nominal standard size
≈ 360 ft
Aircraft
4 referencesfull tip-to-tip wingspan
Rounded manufacturer reference
≈ 68.4 m
overall length
Rounded manufacturer reference
≈ 72.7 m
overall length
Rounded manufacturer reference
≈ 62.8 m
overall length
Manufacturer specification
≈ 37.57 m
Electronics
5 referencesoverall width, with controllers
Manufacturer specification
≈ 242 mm
case width
Manufacturer specification
≈ 60.6 mm
body height
Manufacturer specification
≈ 147.6 mm
body width
Manufacturer specification
≈ 30.41 cm
manufacturer listed width
Rounded manufacturer reference
≈ 358 mm
Science
7 referencesprimary-mirror diameter
Published reference measurement
≈ 6.5 m
volumetric mean diameter
Published reference measurement
≈ 12742.0168 km
volumetric mean diameter
Published reference measurement
≈ 6779.00 km
volumetric mean diameter
Published reference measurement
≈ 139822 km
volumetric mean diameter
Published reference measurement
≈ 49244 km
diameter from rounded radius
Published reference measurement
≈ 3480 km
primary-mirror diameter
Published reference measurement
≈ 2.4 m
Spacecraft
7 referencesvehicle length, without extended arm
Published reference measurement
≈ 3 m
rotor tip-to-tip span
Published reference measurement
≈ 1.2 m
span across solar arrays
Published reference measurement
≈ 109 m
apollo launch stack height
Published reference measurement
≈ 363 ft
orbiter length
Published reference measurement
≈ 122 ft
launch stack height
Published reference measurement
≈ 322 ft
high gain antenna diameter
Published reference measurement
≈ 3.7 m
Landmarks
6 referencesclock-dial diameter
Published reference measurement
≈ 7 m
ground to torch height
Published reference measurement
≈ 92.9894 m
main span between towers
Published reference measurement
≈ 4200 ft
maximum height
Published reference measurement
≈ 630 ft
total tower height
Published reference measurement
≈ 634 m
total building height
Published reference measurement
≈ 508 m
Animals
9 referenceswingspan
Chosen midpoint of a documented range
≈ 3.5 in
ear length
Chosen midpoint of a documented range
≈ 5 in
body length excluding tail
Chosen midpoint of a documented range
≈ 15 in
body length
Chosen midpoint of a documented range
≈ 115 cm
body length excluding tail
Chosen midpoint of a documented range
≈ 22.5 in
standing height
Chosen midpoint of a documented range
≈ 25.5 in
body length
Chosen midpoint of a documented range
≈ 5.5 ft
listed height
Chosen midpoint of a documented range
≈ 4.6 ft
listed bird length
Published reference measurement
≈ 10 in
Fiction
9 referencesofficial Pokédex height
Official fictional reference
≈ 0.4 m
official Pokédex height
Official fictional reference
≈ 0.7 m
official Pokédex height
Official fictional reference
≈ 0.6 m
official Pokédex height
Official fictional reference
≈ 0.5 m
official Pokédex height
Official fictional reference
≈ 0.3 m
official Pokédex height
Official fictional reference
≈ 2.1 m
official Pokédex height
Official fictional reference
≈ 1.7 m
official Pokédex height
Official fictional reference
≈ 1.5 m
official Pokédex height
Official fictional reference
≈ 2.2 m
