Price

The Price class represents an exchange rate between two currencies.

Import

import { Price } from '@uniswap/sdk-core-next'

Constructor

// Option 1: Direct values
new Price(baseCurrency, quoteCurrency, denominator, numerator)
 
// Option 2: From amounts
new Price({ baseAmount, quoteAmount })

Parameters (Option 1)

Name	Type	Description
`baseCurrency`	`TBase`	The base (input) currency
`quoteCurrency`	`TQuote`	The quote (output) currency
`denominator`	`BigintIsh`	The denominator of the price
`numerator`	`BigintIsh`	The numerator of the price

Parameters (Option 2)

Name	Type	Description
`baseAmount`	`CurrencyAmount<TBase>`	Amount of base currency
`quoteAmount`	`CurrencyAmount<TQuote>`	Amount of quote currency

Example

import { Price, Token, CurrencyAmount } from '@uniswap/sdk-core-next'
 
const USDC = new Token(1, '0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48', 6, 'USDC')
const WETH = new Token(1, '0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2', 18, 'WETH')
 
// Create price: 1 ETH = 2000 USDC
// Price is quote/base, so 2000 USDC per 1 ETH
const ethPrice = new Price(
  WETH,
  USDC,
  1n,    // denominator (1 WETH)
  2000n  // numerator (2000 USDC)
)
 
console.log(ethPrice.toSignificant(6)) // "2000"
 
// From amounts
const wethAmount = CurrencyAmount.fromRawAmount(WETH, '1000000000000000000') // 1 WETH
const usdcAmount = CurrencyAmount.fromRawAmount(USDC, 2000_000000n)          // 2000 USDC
 
const priceFromAmounts = new Price({
  baseAmount: wethAmount,
  quoteAmount: usdcAmount,
})
 
console.log(priceFromAmounts.toSignificant(6)) // "2000"

Properties

`baseCurrency`

readonly baseCurrency: TBase

The input currency (denominator of the rate).

`quoteCurrency`

readonly quoteCurrency: TQuote

The output currency (numerator of the rate).

`scalar`

readonly scalar: Fraction

Internal scalar for decimal adjustment.

Methods

`invert()`

invert(): Price<TQuote, TBase>

Returns the inverse price (swap base and quote).

const ethUsdcPrice = new Price(WETH, USDC, 1n, 2000n)  // 2000 USDC/WETH
const usdcEthPrice = ethUsdcPrice.invert()             // 0.0005 WETH/USDC
 
console.log(usdcEthPrice.toSignificant(6)) // "0.0005"

`multiply(other)`

multiply<TOtherQuote extends Currency>(
  other: Price<TQuote, TOtherQuote>
): Price<TBase, TOtherQuote>

Multiply prices to get a derived price. The other price's base must match this price's quote.

const ethUsdc = new Price(WETH, USDC, 1n, 2000n)  // ETH/USDC = 2000
const usdcDai = new Price(USDC, DAI, 1n, 1n)      // USDC/DAI = 1
 
const ethDai = ethUsdc.multiply(usdcDai)           // ETH/DAI = 2000

`quote(currencyAmount)`

quote(currencyAmount: CurrencyAmount<TBase>): CurrencyAmount<TQuote>

Convert an amount of base currency to quote currency using this price.

const ethUsdcPrice = new Price(WETH, USDC, 1n, 2000n)
const wethAmount = CurrencyAmount.fromRawAmount(WETH, '1000000000000000000') // 1 WETH
 
const usdcAmount = ethUsdcPrice.quote(wethAmount)
console.log(usdcAmount.toSignificant(6)) // "2000"

`toSignificant(significantDigits?, format?, rounding?)`

toSignificant(
  significantDigits?: number,  // default: 6
  format?: { groupSeparator?: string },
  rounding?: Rounding
): string

Format the price with significant digits, adjusted for decimal differences.

const price = new Price(WETH, USDC, 1n, 2000n)
price.toSignificant(4)  // "2000"
price.toSignificant(2)  // "2.0e+3"

`toFixed(decimalPlaces?, format?, rounding?)`

toFixed(
  decimalPlaces?: number,  // default: 4
  format?: { groupSeparator?: string },
  rounding?: Rounding
): string

Format the price with fixed decimal places.

const price = new Price(WETH, USDC, 1n, 2000n)
price.toFixed(2)  // "2000.00"
price.toFixed(0)  // "2000"

Example: Price from Pool

import { Price, Token, CurrencyAmount } from '@uniswap/sdk-core-next'
 
// Simulated pool reserves
const wethReserve = CurrencyAmount.fromRawAmount(WETH, '100000000000000000000') // 100 WETH
const usdcReserve = CurrencyAmount.fromRawAmount(USDC, 200000_000000n)           // 200,000 USDC
 
// Price of WETH in terms of USDC
const wethPrice = new Price({
  baseAmount: wethReserve,
  quoteAmount: usdcReserve,
})
 
console.log(`1 WETH = ${wethPrice.toSignificant(6)} USDC`) // "1 WETH = 2000 USDC"
 
// Price of USDC in terms of WETH
const usdcPrice = wethPrice.invert()
console.log(`1 USDC = ${usdcPrice.toSignificant(6)} WETH`) // "1 USDC = 0.0005 WETH"