Unit Conversion

Unit Conversion

NuGet: Nethereum.Util (included in Nethereum.Web3)

Source: tests/Nethereum.ABI.UnitTests/UtilDocExampleTests.cs

Wei to Ether and Back

using System.Numerics;
using Nethereum.Util;

var convert = UnitConversion.Convert;

// Ether to Wei
var UnitConversion.EthUnit.Ether);
// Result: 1000000000000000000

// Wei to Ether
var etherValue = convert.FromWei(BigInteger.Parse("1500000000000000000"));
// Result: 1.5m

Gwei Conversion

var convert = UnitConversion.Convert;

// Gwei to Wei (e.g., gas price)
var gweiInWei = convert.ToWei(21, UnitConversion.EthUnit.Gwei);
// Result: 21000000000

// Wei to Gwei
var gweiValue = convert.FromWei(BigInteger.Parse("21000000000"), UnitConversion.EthUnit.Gwei);
// Result: 21m

Other Denominations

var convert = UnitConversion.Convert;

var finneyInWei = convert.ToWei(1, UnitConversion.EthUnit.Finney);
// Result: 1000000000000000

var szaboInWei = convert.ToWei(1, UnitConversion.EthUnit.Szabo);
// Result: 1000000000000

var ketherInWei = convert.ToWei(1, UnitConversion.EthUnit.Kether);
// Result: 1000000000000000000000

Custom Decimals for ERC-20 Tokens

Use integer decimal places instead of EthUnit for tokens with non-18 decimals (e.g., USDC = 6, WBTC = 8).

var convert = UnitConversion.Convert;

// USDC (6 decimals): raw value to human-readable
var usdcValue = convert.FromWei(BigInteger.Parse("1000000"), 6);
// Result: 1m

// Human-readable to raw value
var usdcRaw = convert.ToWei(1m, 6);
// Result: 1000000

BigDecimal Precision

For very large values where decimal would lose precision, use FromWeiToBigDecimal.

var convert = UnitConversion.Convert;
var largeWei = BigInteger.Parse("123456789012345678901234567890");

var bigDecimal = convert.FromWeiToBigDecimal(largeWei, UnitConversion.EthUnit.Ether);

// Round-trip back to Wei without precision loss
var backToWei = convert.ToWei(bigDecimal, UnitConversion.EthUnit.Ether);
// backToWei == largeWei

Denomination Reference Table

For custom token decimals, pass an int instead of EthUnit:

• USDC/USDT: 6
• WBTC: 8
• DAI/ETH: 18