Convert Words to Numbers

Convert English number words to numbers (and back). Supports negative, billions, quintillions. Free, client-side, instant, secure.

Parse English number words ("forty-two", "one hundred twenty-three", "negative fifteen") into integers, and reverse. Supports up to quadrillion. (This is the same operation as the Words to Integers tool - "numbers" and "integers" share the same parser.)

Type to begin.

How to Use Convert Words to Numbers

  1. Enter English number words, one per line. Supports zero through quadrillion (10^15).
  2. Negative / minus prefix, hyphenated forms, and "and" connectors all work.
  3. Unrecognized words throw with the position so you can see exactly what failed.
  4. Swap direction to convert numbers back to words.

Frequently Asked Questions

Is this the same as the Words to Integers tool?

Yes – same parser, same output, same vocabulary. Two slugs exist because users search both terms. If you find behaviour differences between the two, that’s a bug; report it.

How are bare scale words like “hundred” handled?

They default to one of the scale: "hundred" → 100, "thousand" → 1,000, "million" → 1,000,000. That matches everyday speech, where “hundred” on its own means one hundred.

What number vocabulary is supported?

Ones (zero-nine), teens (ten-nineteen), tens (twenty-ninety), and scales (hundred, thousand, million, billion, trillion, quadrillion). Plus “negative” / “minus” prefix and “and” connector. Anything else throws an explicit error.

How does quintillion fit?

Quintillion = 10^18 exceeds JavaScript’s Number.MAX_SAFE_INTEGER (2^53 – 1 ≈ 9.007 × 10^15). The reverse direction caps at quadrillion to preserve accuracy. Forward parsing accepts “quintillion” but the result loses precision around 10^15. For exact arithmetic above that range, use BigInt outside this tool.

What if I want “a hundred” or “a thousand”?

Not supported. Use one hundred, one thousand. (The article “a” isn’t in the dictionary.)

Ordinals?

Not supported. “first”, “twenty-third”, “fifth” all error. Use cardinal forms instead.

Decimals?

Not supported. “three point five”, “two and a half” error. For decimal word parsing, use a dedicated tool with “point” / “decimal” handling.

What if I have mixed text like “five potatoes”?

It errors with Unrecognized word at position 2: "potatoes". The tool only handles pure number-word strings – it won’t extract numbers from prose.

Does it handle British “billion”?

Short-scale (modern) billion = 10^9 is used here. Long-scale (historical) billion = 10^12 is no longer commonly used in UK English either. For long-scale, multiply manually.

Is text uploaded?

No. Everything runs in your browser with JavaScript – nothing is sent to a server, logged, or stored, and the tool keeps working offline once the page has loaded.