canirequire › ESM-only › @csstools/css-calc
Is @csstools/css-calc ESM-only? Can you require() it?
Solve CSS math expressions
Last verified Sep 9, 2026 against @csstools/css-calc@3.3.0. Markdown · JSON
ESM-only ESM-only since 3.0.0 — last CommonJS version is 2.1.4
@csstools/css-calc dropped its CommonJS build in 3.0.0 (January 2026). The last version with a plain require()-able CommonJS entry is 2.1.4, published May 27, 2025; it declares support for Node.js >=18.
On Node.js 20.19+, 22.12+ and newer, require("@csstools/css-calc") works with the latest version: Node.js loads synchronous ES modules through require(). Verified on Node.js 20, 22, 24 and 26. Node.js 18 has no require(esm), and @csstools/css-calc@3.3.0 declares Node.js >=20.19.0, so 18 is outside its supported range anyway.
@csstools/css-calc@3.3.0 declares engines ">=20.19.0", so Node.js 18 is outside its supported range regardless of module format.
What to do
- On Node.js 20.19+, 22.12+ and newer, require("@csstools/css-calc") works with the latest version: Node.js loads synchronous ES modules through require(). Verified on Node.js 20, 22, 24 and 26.
- From a CommonJS file, use a dynamic import inside an async function: const cssCalc = await import("@csstools/css-calc"). That works on every Node.js version the package supports (>=20.19.0).
- If you need a synchronous require() or run Node.js 18: npm install @csstools/css-calc@2.1.4, the last CommonJS release (published May 27, 2025); it declares Node.js >=18.
- @csstools/css-calc@3.3.0 declares engines ">=20.19.0", so Node.js 18 is unsupported regardless: upgrade Node.js or pin an older release.
- TypeScript: types are bundled; install nothing extra.
Does @csstools/css-calc@3.3.0 actually load? Runtime test results
Installed and executed on Sep 9, 2026 with require("@csstools/css-calc") from a CommonJS file and import "@csstools/css-calc" from an ES module.
| Runtime | require("@csstools/css-calc") | import "@csstools/css-calc" |
|---|---|---|
| Node.js 18 | ✗ failsERR_REQUIRE_ESM | ✓ works |
| Node.js 20 | ✓ works | ✓ works |
| Node.js 22 | ✓ works | ✓ works |
| Node.js 24 | ✓ works | ✓ works |
| Node.js 26 | ✓ works | ✓ works |
| Bun 1.4.0 | ✓ works | ✓ works |
How to import @csstools/css-calc
ES modules (import)
import * as cssCalc from "@csstools/css-calc";Namespace import shown because the ESM entry may have no default export; use named imports for what it exports.
CommonJS (require)
// Node.js 20.19+, 22.12+ and newer (verified):
const cssCalc = require("@csstools/css-calc");
// Any Node.js version the package supports (>=20.19.0), from an async function:
async function main() {
const cssCalc = await import("@csstools/css-calc");
}
// Or pin the last CommonJS release (declares Node.js >=18):
// npm install @csstools/css-calc@2.1.4Module format by version
Derived from the type, main and exports fields of every stable release on npm, corrected where a runtime test of that version contradicted them (32 versions; the newest 32 shown).
| Versions | Format | First published |
|---|---|---|
| 3.0.0 – 3.3.0 | ESM-only | Jan 14, 2026 |
| 1.0.0 – 2.1.4 | Dual (CommonJS + ESM) | Feb 21, 2023 |
Frequently asked
Is @csstools/css-calc ESM-only?
@csstools/css-calc@3.3.0 is ESM-only. @csstools/css-calc dropped its CommonJS build in 3.0.0 (January 2026). The last version with a plain require()-able CommonJS entry is 2.1.4, published May 27, 2025; it declares support for Node.js >=18.
Which version of @csstools/css-calc still supports CommonJS / require()?
2.1.4 is the last version of @csstools/css-calc with a CommonJS build; it declares Node.js >=18. Install it with "npm install @csstools/css-calc@2.1.4". Every version from 3.0.0 on is ESM-only.
How do I use @csstools/css-calc from a CommonJS file?
From a CommonJS file, use a dynamic import inside an async function: const cssCalc = await import("@csstools/css-calc"). That works on every Node.js version the package supports (>=20.19.0). On Node.js 20.19+, 22.12+ and newer, require("@csstools/css-calc") works with the latest version: Node.js loads synchronous ES modules through require(). Verified on Node.js 20, 22, 24 and 26. Alternatively pin @csstools/css-calc@2.1.4 (declares Node.js >=18).
Does @csstools/css-calc work in Bun?
Yes. import "@csstools/css-calc" loaded successfully in Bun 1.4.0 on Sep 9, 2026.
Does @csstools/css-calc ship TypeScript types?
Yes. @csstools/css-calc bundles its own type declarations; no @types package is needed.
Links
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4.0.0
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