---
title: "Enormous decimal values"
package: "@phaser-ae/large-number"
tier: Free
version: 3.0.0-4
released: 2026-10-14
updated: 2026-10-20
description: "Forty-digit decimal arithmetic for idle-game currencies, prices and scores that outgrow ordinary numbers, with explicit rounding and readable formatting."
url: https://phaser.io/packs/large-number
site: Phaser - https://phaser.io
---

# Enormous decimal values

Decimal arithmetic for huge game currencies, prices and production. Values keep forty significant digits and an exponent
up to a billion, and never pass through a JavaScript number that would overflow or lose digits.

## What it does

Ordinary JavaScript numbers lose exact integer precision above about nine quadrillion and overflow to infinity above
about 1.8e308. An idle game can pass both long before its endgame. A `LargeNumber` holds a forty-digit decimal
coefficient and an exponent, so a balance of `1.23456789e400` subtracts a price of `9e398` correctly, and 1e1000000 is
still just a number.

Values are immutable. `compare`, `add`, `subtract`, `multiply`, `divide`, whole-number `pow`, `sqrt`, `negate`, `abs`
and `round` each return a new value, and those that can lose digits take a rounding mode: `half-even` (the default),
`floor`, `ceil` or `trunc`. That is what keeps an economy honest: a cost can round up and a balance down, so a player
can never buy something they cannot quite afford. `round` takes negative places too, to round to thousands, billions or
multiples of 1e400.

Display is part of the pack. `format` shows a value as compact suffixes, full short-scale names from thousand to
vigintillion plus centillion, scientific, engineering or plain digits, at one to forty significant digits, and rolls
999,999,999 at three digits over to `1 B` correctly. Input text accepts the same names, so `'1.5 nonillion'` is a valid
value, and `toString` and `toJSON` keep every stored digit for saves.

## Features

- **Forty significant digits** — with exponents from minus a billion to plus a billion.
- **Directed rounding** — `half-even`, `floor`, `ceil` and `trunc` wherever digits can be lost, and rounding to any
  power of ten.
- **Full arithmetic** — add, subtract, multiply, divide, integer powers, square roots and comparison.
- **Readable formatting** — `compact`, `named`, `scientific`, `engineering` and `plain`, with a chosen number of digits.
- **Named input** — text such as `'2 centillion'`, case-insensitive, alongside scientific notation.
- **JSON-safe** — canonical decimal text in saves, read back exactly.
- **Explicit failures** — division by zero, negative square roots, bad formats and out-of-range exponents throw rather
  than quietly giving nonsense.

## Good for

- **Idle and incremental games**, where currency and production climb through hundreds of orders of magnitude.
- **Clicker games** with prices in the octillions and upgrades that multiply them.
- **Enormous scores** that pass what an ordinary number holds exactly.
- **Scientific-style quantities** shown in engineering or scientific notation.

## Make it yours

The pack has no options; the choices are per call. Each operation takes its rounding mode, and formatting takes a
notation and a number of significant digits. Two different uses: an idle business game that formats every price `named`
at three digits ("12.5 quadrillion") and rounds costs with `ceil`; and a space game that shows distances in `scientific`
notation and rounds them to the nearest 1e9 for its readout.

## A quick look

A balance, a price and the result, formatted and saved:

```ts
const balance = game.largeNumbers.largeNumber('1.23456789e400');
const price = game.largeNumbers.largeNumber('9e398');
const after = balance.subtract(price, 'floor');
after.format();                         // '11.45e+399'
game.largeNumbers.largeNumber('2500000000').round(-9); // 2e9 (ties to even)
JSON.stringify(after);                  // canonical decimal string
```

## Works with

- `incremental` — idle business ladders and mine pipelines with every price and balance held in these values.
- `save` — keeps the JSON text between visits.

## Good to know

- Forty significant digits is a game decimal, not unlimited exact integers; use native `BigInt` when every digit
  matters, and do not use it for financial accounting.
- `toNumber()` is an approximate conversion for ratios and screen positions; never pass a balance through it.
- Inputs are limited to 4096 characters, powers to a million either way, and plain display to about 4096 characters.

---

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