# General Translation Platform: formatNum URL: https://generaltranslation.com/en-GB/docs/platform/core/reference/utility-functions/formatting/format-num.mdx Docs index: https://generaltranslation.com/llms.txt Description: Format numbers, currency, percentages and numeric values without a GT instance. API reference for formatNum. [`formatNum`](/docs/platform/core/reference/gt-class-methods/formatting/format-num) is a standalone utility function from General Translation's core library that formats numbers according to locale-specific conventions. It returns a locale-aware string for decimals, currency, percentages and units. ## Overview [#overview] Import `formatNum` directly from `generaltranslation` and call it with the number to format and an options object. It does not require an API key or a [GT](/docs/platform/core/reference/gt-class/constructor) instance, so use it anywhere you need one-off number formatting. For instance-based formatting that inherits the instance locale, use the [`formatNum`](/docs/platform/core/reference/gt-class-methods/formatting/format-num) method on a [`GT`](/docs/platform/core/reference/gt-class/constructor) instance instead. ```typescript import { formatNum } from 'generaltranslation'; const formatted = formatNum(1234.56, { locales: 'de-DE', style: 'currency', currency: 'EUR', }); // Returns: "1.234,56 €" ``` Signature: ```typescript formatNum( number: number, options?: { locales?: string | string[] } & Intl.NumberFormatOptions ): string ``` ## How it works [#how-it-works] * **Underlying API.** Uses the same [`Intl.NumberFormat`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/NumberFormat) as the GT class method, so all standard `Intl.NumberFormat` options are supported. * **Locale resolution.** When `locales` is an array, locales are tried in order and the first supported locale is used. When `locales` is omitted, it falls back to the library default locale, `en`. * **Caching.** Results are cached internally for performance across repeated locale and options combinations. ## Parameters [#parameters] | Parameter | Description | Type | Optional | Default | | --------------------- | --------------------------------------------------------------------------------------------- | ------------------------------------------------------------- | -------- | ------- | | [`number`](#number) | The number to format. | `number` | No | — | | [`options`](#options) | Formatting configuration, including the target locale(s) and any `Intl.NumberFormat` options. | `{ locales?: string \| string[] } & Intl.NumberFormatOptions` | Yes | `{}` | ### `number` [#number] **Type** `number` · **Required** The numeric value to format. ### `options` [#options] **Type** `{ locales?: string | string[] } & Intl.NumberFormatOptions` · **Optional** · **Default** `{}` Formatting configuration. The table lists common options exposed by the published Core types and their effective Core defaults. (See the [`Intl.NumberFormat` constructor options](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/NumberFormat/NumberFormat#options) for supplementary standard and runtime-specific details). | Property | Description | Type | Optional | Default | | -------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------- | -------- | ---------------------------------------------------------------------------------------------------- | | `locales` | Locale(s) for formatting. Tried in order when an array is passed. | `string \| string[]` | Yes | `en` | | `localeMatcher` | Locale matching algorithm. | `'lookup' \| 'best fit'` | Yes | `'best fit'` | | `numberingSystem` | Numbering system, such as `latn` or `arab`. | `string` | Yes | `'latn'` | | `style` | Number formatting style. | `'decimal' \| 'currency' \| 'percent' \| 'unit'` | Yes | `'decimal'` | | `currency` | Currency code (required when `style` is `'currency'`). | `string` | Yes | — | | `currencyDisplay` | How to display the currency. | `'symbol' \| 'narrowSymbol' \| 'code' \| 'name'` | Yes | `'symbol'` | | `currencySign` | Currency sign to use. | `'standard' \| 'accounting'` | Yes | `'standard'` | | `unit` | Unit identifier (required when `style` is `'unit'`). | `string` | Yes | — | | `unitDisplay` | How to display the unit. | `'short' \| 'narrow' \| 'long'` | Yes | `'short'` | | `minimumIntegerDigits` | Minimum number of integer digits (1–21). | `number` | Yes | `1` | | `minimumFractionDigits` | Minimum fraction digits (0–100). The style affects the default. | `number` | Yes | `0` for decimal/percent; currency minor-unit digits for currency; `0` with compact defaults | | `maximumFractionDigits` | Maximum fraction digits (0–100). The style and minimum affect the default. | `number` | Yes | `3` for decimal; `0` for percent; currency minor-unit digits for currency; `0` with compact defaults | | `minimumSignificantDigits` | Minimum significant digits (1–21), when significant-digit rounding is active. | `number` | Yes | `1` | | `maximumSignificantDigits` | Maximum significant digits (1–21), when significant-digit rounding is active. | `number` | Yes | `21`; `2` with compact defaults | | `roundingPriority` | How fraction- and significant-digit settings interact. | `'auto' \| 'morePrecision' \| 'lessPrecision'` | Yes | `'auto'`; `'morePrecision'` with compact defaults | | `notation` | Number notation format. | `'standard' \| 'scientific' \| 'engineering' \| 'compact'` | Yes | `'standard'` | | `compactDisplay` | Compact notation display style. | `'short' \| 'long'` | Yes | `'short'` | | `useGrouping` | Whether and when to use grouping separators. | `boolean \| 'always' \| 'auto' \| 'min2'` | Yes | `'auto'`; `'min2'` with compact notation | | `signDisplay` | When to display the sign. | `'auto' \| 'never' \| 'always' \| 'exceptZero' \| 'negative'` | Yes | `'auto'` | | `roundingMode` | Rounding mode. | `'ceil' \| 'floor' \| 'expand' \| 'trunc' \| 'halfCeil' \| 'halfFloor' \| 'halfExpand' \| 'halfTrunc' \| 'halfEven'` | Yes | `'halfExpand'` | | `roundingIncrement` | Rounding increment. Non-default values require equal effective minimum and maximum fraction digits and cannot be combined with significant-digit rounding or a non-`'auto'` `roundingPriority`. | `1 \| 2 \| 5 \| 10 \| 20 \| 25 \| 50 \| 100 \| 200 \| 250 \| 500 \| 1000 \| 2000 \| 2500 \| 5000` | Yes | `1` | | `trailingZeroDisplay` | Whether to display trailing zeros. | `'auto' \| 'stripIfInteger'` | Yes | `'auto'` | When `notation: 'compact'` is set without any fraction- or significant-digit option, the effective digit defaults are `minimumFractionDigits: 0`, `maximumFractionDigits: 0`, `minimumSignificantDigits: 1`, and `maximumSignificantDigits: 2`. In that case, `roundingPriority` defaults to `'morePrecision'` and `useGrouping` defaults to `'min2'`. ## Returns [#returns] **Type** `string` The number formatted according to locale conventions. ## Examples [#examples] ```typescript import { formatNum } from 'generaltranslation'; // Basic number formatting console.log(formatNum(1234.567, { locales: 'en-US' })); // Output: "1,234.567" // German formatting console.log(formatNum(1234.567, { locales: 'de-DE' })); // Output: "1.234,567" ``` ```typescript // Currency formatting // US Dollar console.log(formatNum(1234.56, { locales: 'en-US', style: 'currency', currency: 'USD', })); // Output: "$1,234.56" // Euro with German locale console.log(formatNum(1234.56, { locales: 'de-DE', style: 'currency', currency: 'EUR', })); // Output: "1.234,56 €" // Japanese Yen console.log(formatNum(1234.56, { locales: 'ja-JP', style: 'currency', currency: 'JPY', })); // Output: "¥1,235" ``` ## Notes [#notes] * Uses the same underlying `Intl.NumberFormat` as the GT class method. * Results are cached internally to improve performance for repeated locale/options combinations. * Fallback locales are processed in order if the primary locale is not supported. * All standard `Intl.NumberFormat` options are supported. ## Sitemap See the full [sitemap](https://generaltranslation.com/sitemap.md) for all pages.