Convert Words to Numbers

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.

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.

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.

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.

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

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

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

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

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.

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.