num vs bigdecimal

Short answerBy steady daily use, num is bigger: 811,973 real downloads a day against 365,613 for bigdecimal (2.2x). 2,024 crates depend on num and 588 on bigdecimal. num last shipped 21 months ago, bigdecimal 26 days ago.

num

Widely used

Widely used and gaining.

2,024 crates depend on it; no release in the last 90 days, so its count is all steady use.

A collection of numeric types and traits for Rust, including bigint, complex, rational, range iterators, generic integers, and more!

bigdecimal

Established

Established and steady.

588 crates depend on it; small bumps on release days (1.25x the baseline).

Arbitrary precision decimal numbers

numbigdecimal · 100% = that crate's normal quiet day, so a spike to 300% is triple its usual traffic

Every number, side by side

Same window, same method	num	bigdecimal
Real downloads a day	811,973	365,613
Crates that depend on it	2,024	588
Last release	0.1.43, 21 months ago	0.4.11, 26 days ago
Trend vs the field	+11%	-4%
Release-window share	0.0%	2.8%
Downloads in the window	75,354,739	32,909,523
All-time downloads	318,637,312	134,139,905
Versions published	58	27
License	MIT/Apache-2.0	MIT/Apache-2.0
MSRV	not set	not set
First published	Nov 11, 2014	Apr 5, 2017

Which to pick

Downloads tell you what is common, not what fits. Each crate's own description above says what it is for; when the jobs differ, pick by the job.
When both fit, prefer the one more crates depend on (num, 2,024 dependents): more eyes, more answered questions, and you may already have it in your tree.
Check the release dates against your own pace: num 21 months ago, bigdecimal 26 days ago.

Also in this space

number_prefixPulled inLibrary for numeric prefixes (kilo, giga, kibi)280,493 a day, 39 dependentscrypto-bigintEstablishedPure Rust implementation of a big integer library which has been designed from the ground-up for use in...937,488 a day, 167 dependents crossbeam-utilsEstablishedUtilities for concurrent programming2,696,777 a day, 605 dependents ahashWidely usedA non-cryptographic hash function using AES-NI for high performance1,968,676 a day, 2,097 dependents

Compare 4 of them side by side →

Method

Real downloads = the median day with no release that day or the day before, from the crates.io API (Jul 27, 2026 to Oct 23, 2026). Raw crates.io counts include CI and bots and run high (why); the method is from our 90-day study.

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