What Is the Wingspan of a Monarch Butterfly? 9.5 cm

Compared with things you know

About 3.9 times the width of a US quarter coin (2.43 cm)
About 1.1 times the width of a credit card (8.56 cm)
About 40% of the width of a basketball (24 cm)

Monarch butterfly 9.5 cm
Credit card 8.56 cm
Basketball 24 cm

Drawn to scale: Credit card, 8.56 cm wide · Monarch butterfly, 9.5 cm wingspan · Basketball, 24 cm across

Monarch butterfly dimensions

Measurement	Metric	Imperial	Source
Wingspan	9.5 cm95 mm	3.74 in	^[1]^[2]
Caterpillar length (fully grown)	4.5 cm45 mm	1.772 in	^[1]
Egg length	1.2 mm	0.047 in	^[1]

Monarch sizes by life stage^[1]^[2]

Adult wingspan (Wikipedia)	8.9–10.2 cm (3.5–4.02 in)
Adult wingspan (Illinois DNR)	8.26–12.4 cm (3.25–4.87 in)3 1/4 to 4 7/8 in
Caterpillar, fully grown	4.5–5 cm (1.77–1.97 in)Large specimens can reach 5 cm
Chrysalis	2.5 cm (0.984 in)About 2.5 cm
Egg	1.2 mm (0.0472 in)About 1.2 x 0.9 mm

Wingspan

Wikipedia gives the wingspan of an adult monarch as 8.9 to 10.2 cm (3.5 to 4.0 in). The Illinois Department of Natural Resources gives a wider range, three and one-fourth to four and seven-eighths inches (about 8.3 to 12.4 cm). The game uses 9.5 cm, which falls inside both ranges. Sources do not agree on a single typical value, so treat the wingspan as a range.^[1]^[2]

Males, females and migrants

Males tend to have larger wings than females and are typically heavier. The University of Florida says monarchs reaching Cuba differ from the resident population in wing length and shape, so size also varies between populations. The pages cited here give no measurements for these differences.^[1]^[3]

From egg to adult

A monarch grows a great deal between stages. The egg is about 1.2 mm by 0.9 mm (0.047 by 0.035 in). When fully grown the caterpillar is 4.5 cm (1.8 in) long, and large specimens can reach 5 cm (2.0 in). The chrysalis is about 2.5 cm (0.98 in) long. The adult that emerges spans 8.9 to 10.2 cm with its wings open.^[1]