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Number Formatter

A number formatter turns a raw number into a styled string — currency ($1,234.56), percent (12.5%), scientific notation (1.50e+06), engineering notation (1.50M), or custom (format-string driven). Useful when downstream systems need a specific shape, when localising for international audiences, or when generating reports with consistent formatting. The ZTools Number Formatter wraps the browser's Intl.NumberFormat API plus a custom format-string engine, supports 100+ locales, and runs entirely client-side.

Use cases​

Generate localised currency strings​

Same value, different locales: $1,234.56 (US), £1,234.56 (UK), 1.234,56 € (DE), ¥1,235 (JP). One source, many outputs.

Format dashboard numbers compactly​

"$1,234,567" doesn't fit; "$1.23M" does. Compact notation gives readable summary tiles.

Format percentages​

0.125 → 12.5%. Standard for displaying ratios and conversion rates.

Scientific notation for engineering​

0.000000123 → 1.23 × 10⁻⁷. Easier to read at a glance for orders-of-magnitude work.

How it works​

  1. Paste number — Single value or list. Tool detects format.
  2. Pick style — Decimal (1,234.56), currency, percent, scientific, engineering, or compact (1.23M).
  3. Configure — Locale, currency code (USD, GBP, EUR, ...), decimal places, sign style.
  4. Read output — Formatted string — ready to paste into a report, UI mockup, or code.

Examples​

Input: 1234.56, currency USD

Output: $1,234.56 (en-US). $1,234.56 USD (en-CA). USD 1,234.56 (de-DE forced USD).

Input: 0.125, percent

Output: 12.5%.

Input: 1500000, compact

Output: 1.5M (en) / 1,5 Mio. (de) / 150万 (ja). Locale-aware abbreviations.

Input: 0.0000123, scientific

Output: 1.23E-5 / 1.23 × 10⁻⁵.

Frequently asked questions​

What's the difference between compact and scientific?

Compact uses locale abbreviations (M, K, B). Scientific uses powers of 10. Compact is for casual reading; scientific for precision and engineering.

How do I choose decimals?

Default is 2 (currency) or "as-needed" (decimal). Lock to specific count for consistency in tables. Don't round below the precision you need to communicate.

Locale support?

All Intl.NumberFormat-supported locales (~100+). Major ones cover ~99% of use cases.

Custom format strings?

Toggle "custom" to use printf-style format: "%.2f%%" → "12.50%". Familiar to Excel / SQL / Python users.

Privacy?

All client-side.

Tips​

  • For dashboards, prefer compact notation — saves space without losing meaning at a glance.
  • For finance / accounting, lock decimal places. "$1,234.5" and "$1,234.50" should never appear in the same report.
  • For percentages, use the percent style not "x × 100 + %" — locale-aware percent style handles RTL languages and unusual locales correctly.
  • When integrating with code, use Intl.NumberFormat directly — this tool is for one-off / prototyping use.

Try it now​

The full Number Formatter runs in your browser at https://ztools.zaions.com/number-formatter — no signup, no upload, no data leaves your device.

Open the tool ↗

Last updated: 2026-05-06 · Author: Ahsan Mahmood · Edit this page on GitHub