Lodash Math Methods

Beginner
5 min read
Updated: Nov 2026
15 method guides
Method index
Lodash Math methods index — _.add, _.round, _.max, _.sum, and more
Index

About This Index

This page is the Lodash Math index for the tutorial track. Each row links to a full guide with syntax, examples, and FAQs.

Learn lang checks on /lodash/lang. Use this page when you need math helpers such as _.add(), _.round(), or _.sum().

Beginner path.

Start with _.add(), then _.round(), _.max(), and _.sum()—then open the *By variants for object arrays.

Syntax

How to Call a Math Method

Pass numbers (or an array for aggregators) to the Lodash helper:

Lodash
import _ from "lodash";

_.add(6, 4);           // 10
_.subtract(6, 4);      // 2
_.multiply(6, 4);      // 24
_.divide(6, 4);        // 1.5

_.round(4.006, 2);     // 4.01
_.ceil(6.004, 2);      // 6.01
_.floor(0.046, 2);     // 0.04

_.max([4, 2, 8, 6]);   // 8
_.sum([4, 2, 8, 6]);   // 20
_.mean([4, 2, 8, 6]);  // 5

_.maxBy([{ n: 1 }, { n: 2 }], "n"); // { n: 2 }
Browse

Lodash Math Methods Table

All math method guides in this Lodash tutorial series (15 tutorials).

Arithmetic

4 methods

Add, subtract, multiply, and divide two numbers.

MethodDescriptionTutorial
_.add()Add two numbers. Undefined operands are treated as 0.Try it
_.subtract()Subtract the second number from the first. Undefined operands are treated as 0.Try it
_.multiply()Multiply two numbers. Undefined operands are treated as 1.Try it
_.divide()Divide two numbers. Undefined operands are treated as 1.Try it

Rounding

3 methods

Ceil, floor, and round with optional precision.

MethodDescriptionTutorial
_.ceil()Round a number up. Supports precision, including negative precision.Try it
_.floor()Round a number down. Supports precision, including negative precision.Try it
_.round()Round a number. Supports precision; negative precision rounds to tens/hundreds.Try it

Min & Max

4 methods

Find extremes in an array, optionally by iteratee.

MethodDescriptionTutorial
_.max()Largest element in an array. Returns undefined when the array is empty.Try it
_.maxBy()Like max, but each element is ranked by an iteratee.Try it
_.min()Smallest element in an array. Returns undefined when the array is empty.Try it
_.minBy()Like min, but each element is ranked by an iteratee.Try it

Aggregate

4 methods

Sum and mean over arrays, with iteratee variants.

MethodDescriptionTutorial
_.sum()Sum of an array of numbers. Returns 0 when the array is empty.Try it
_.sumBy()Like sum, but each element is projected by an iteratee before adding.Try it
_.mean()Arithmetic mean of an array of numbers. Returns NaN when empty.Try it
_.meanBy()Like mean, but each element is projected by an iteratee first.Try it

Frequently Asked Questions

Fifteen helpers for arithmetic (_.add, _.subtract, _.multiply, _.divide), rounding (_.ceil, _.floor, _.round), extremes (_.max, _.min), and aggregates (_.sum, _.mean)—plus *By iteratee variants.
Arithmetic helpers treat undefined as identity values (0 for add/subtract, 1 for multiply/divide), so they work well inside _.reduce. Empty arrays return undefined for max/min, 0 for sum, and NaN for mean—not ±Infinity.
Ceil, floor, and round accept a precision argument. Positive precision keeps decimal places; negative precision rounds to tens, hundreds, and beyond (for example, _.round(4060, -2) → 4100).
Prefer per-method imports: import sum from 'lodash/sum' or import { sum } from 'lodash-es'. You can also use const _ = require('lodash') and call _.sum().
Start with _.add(), then _.round(), _.max(), and _.sum() from the table below.

Start with _.add()

Open the addition guide—syntax, examples, and FAQs.

_.add() tutorial →

About the author

Mari Selvan M P
Mari Selvan M P 🔗

Developer, cloud engineer, and technical writer

  • Experience 12 years building web and cloud systems
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I write practical tutorials so students and working developers can learn by doing—from databases and APIs to deployment on AWS.

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