black widow spider compared with human hand

Black Widow Spider Size Explained & Compared With Other Spiders

Last Updated on April 10, 2023 by Amin Tawar

Black Widow Spider Length

Black Widow Spider Size

Latrodectus mactans is a venomous spider species in the genus Latrodectus. It is also known as the southern black widow or plainly the black widow. 

The black widow spider is one of the few venomous spiders found in North America. A black widow spider bite can cause painful swelling around the bite. 

You may also experience muscle spasms, cramps, and achiness, as well as nausea. Furthermore, females of the species are well recognized for their distinct black and red coloring and for occasionally eating their mates after reproduction.

Black widow spiders are notorious spiders that can be identified by the colored, hourglass-shaped mark on their abdomens, as well as by their size. 

Their overall body length and leg span, in particular. The female black widow, for example, is about 25-38 mm (1-1.5 in) long. 

The male is roughly half the size of the female, about 1.8 inches (3-4 mm). The Black widow’s average overall body length ranges from 3 to 10 mm. Moreover, the leg span of the Black widow spider is about one-half inch long.

Black Widow SpiderCentimeter Inches 
Body lengthMale: 0.3-1 cm Female: 0.25- 1.3 cm Male: 0.1–0.3 in Female: 0.07-0.5 in
Leg span 1.27½ inch 

Black Widow Spider Weight

Black widow spiders eat meat. They eat insects caught in their web, and the female will sometimes kill and eat the male spider, hence the name “black widow.” 

Insects are the primary food of Black Widows. They eat woodlice, chilopods, diplopods, and other arachnids as well. 

Talking about the size of the Black widow spider in terms of its weight, it approximately weighs about 0.035 ounces. The Black widow spiders are quite lightweight. 

Black Widow SpiderOunce Kilograms 
Weight 0.035 ounces0.000992

What Is The Largest Black Widow Spider Size?

Black widow spiders have bodies that range in size from 3 to 10 mm (0.12-0.39 in); some females can measure 13 mm (0.51 in) in length (not including legs). Female adult black widows are typically 25-38 mm long, including their legs (1–1.5 in).

The Phinda button is native to South Africa’s critically endangered sand forests and may be the world’s largest widow spider – certainly the largest in Africa. 

The species is considered a very large spider as its overall length ranges between 10-11 mm for females and 4-5 mm for males. 

Compared to the Black widow spiders these Phinda button spiders, of the same family, are much more significant. 

Black Widow Spider Size Compared With Human Hand

Black Widow Spider Size compared with human hand

Black Widow Spider Vs Tarantula Size Comparison

Are you wondering about what would happen in a fight between the largest spiders and the Black Widow spider? 

Let me tell you! When it comes to size, the tarantula wins by a wide margin. Tarantulas are among the world’s largest spiders, with the Goliath bird-eating tarantula being the largest of all. 

Brown tarantulas can reach leg spans of over 4 inches and have large, heavy bodies. A tarantula can weigh up to 3 oz as an adult. The Goliath can grow to be 11 inches long, with a 12-inch leg span, and weigh 6 ounces.

On the other hand, while Black widows are large spiders, they pale in comparison to a fully-grown tarantula. 

Their bodies are typically less than an inch long and weigh only 0.035 oz when fully grown. 

In comparison, the tarantula weighs 85 times more than the small Black widow spiders. Overall the Black spider is smaller in length and very lightweight. 

Spider type Body lengthLeg span Weight 
Black widow spider 0.3-1.5 inches 0.5 inches 0.035 ounces
Goliath Bird Eating Tarantula11 inches 12 inches 6 ounces 

Black Widow Spider Vs Brown Recluse Size Comparison

Black Widow Spider Size compared with other spiders

The black widow spider and the brown recluse spider have numerous distinctions. Overall, the black widow spider grows more prominent than the brown recluse spider. 

In other words, a brown recluse spider is much smaller than a black widow spider. Brown recluse spiders, for example, can grow to be a quarter of an inch to a 3/4 of an inch long, whereas black widow spiders can grow to be 1 to 2 inches long.

To be more specific, the Brown Recluse spiders are very small, rarely growing to be more than 1/2 inch in length. Additionally, the Brown recluse spiders have a body length ranging from 6 to 20 millimeters (0.24 to 0.79 in) and a leg span of about 2.5 cm. 

Their weight varies between 0.001 lbs. Compared to the Widow spider, these are almost half in overall body length, leg span, and weight. 

Spider type Body lengthLeg span Weight 
Black widow spider 0.3-1.5 inches ½ inch 0.035 ounces
Brown Recluse0.24 to 0.79 inches1 inch 0.016 ounces

Black Widow Spider Vs Brown Widow Size Comparison

Both of these spiders are from the same family, and the only difference between the two is their appearance. 

One looks black while the other is brown in color. While both of these spiders are members of the same family, black widow spiders are larger than brown widow spiders.

There isn’t much of a size difference between them, but if you look closely, you’ll notice that Brown widow spiders are slightly smaller than Black widow spiders.

Brown widow spiders can grow to be half an inch to a full inch long, while black widow spiders can grow to be one and a half inches to two inches long. Although the Black spider is slightly larger in length, the Brown widow spider has quite a long leg span.

Spider type Body lengthLeg span Weight 
Black widow spider 0.3-1.5 inches ½ inch 0.035 ounces
Brown widow spider 0.5 to 1 inch1.5 to 2 inchesLighter than Black widow

Black Widow Spider Vs Orb Weaver Size Comparison

Orb-weaver spiders are Araneidae spiders. Surprisingly, they are the most common group of web builders. The Golden orb weavers are one of the most common orb weavers.

Females have a body length of 2 to 6 inches, while males have a shorter body length of 0.5 to 2 inches. The spiders have 4-5 inches (10-12 centimeter) leg spans and weigh about.

In comparison to the Black widow spider, the Golden orb weaver is much more prominent in terms of all body length, leg span, and weight. 

Spider Type Body lengthLeg span Weight 
Black widow spider 0.3-1.5 inches ½ inch 0.035 ounces
Golden Orb Weaver 0.5-6 inches 4-5 inches0.1-.14 ounce 


And that was everything you need to know about the size of the black widow spider. I hope this article was helpful and you got something valuable from it.

Thank You For Reading!

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