How many wei are in one ether?

One ether equals exactly 10 to the power of 18 wei, that is 1,000,000,000,000,000,000 wei. Wei is the smallest indivisible unit of ether, named after Wei Dai, and all on-chain value arithmetic is performed in integer wei to avoid rounding errors.

What is gwei used for?

Gwei, equal to 10 to the power of 9 wei or one billionth of an ether, is the standard unit for expressing gas prices and EIP-1559 priority fees. Quoting a gas price as 25 gwei is far more readable than writing it out as 25,000,000,000 wei.

Why does this tool compute in wei?

Floating-point math loses precision on the very large numbers involved with wei, which can corrupt transaction amounts. This converter parses your input into an exact integer number of wei using BigInt, so conversions are precise to the last unit even for fractional ether inputs.

What are szabo and finney?

They are intermediate denominations: szabo is 10 to the 12 wei (one microether) and finney is 10 to the 15 wei (one milliether), named after Nick Szabo and Hal Finney. They are rarely used today but appear in older documentation and some libraries.

How do I read the hexadecimal output?

The hex value is the exact wei amount encoded in base 16 with a 0x prefix, which is the format Ethereum JSON-RPC calls and raw transaction fields expect for value and gas. You can paste it directly where a hex quantity is required.

Ether Unit & Scientific Notation Converter

Ethereum uses many named denominations, but every value on-chain is ultimately an integer count of wei, the smallest unit. This converter takes a value in any standard unit and converts it precisely across all of them, then shows the result in decimal, scientific notation, and hexadecimal wei. All arithmetic is done in exact integers using BigInt, so there is no floating-point drift even for fractional ether inputs.

How it works

Each unit is defined by its power-of-ten relationship to wei:

wei    = 1                 (10^0)
kwei   = 1,000             (10^3)
mwei   = 1,000,000         (10^6)
gwei   = 10^9
szabo  = 10^12
finney = 10^15
ether  = 10^18

The tool parses your input, including a decimal fraction, and scales it into an exact integer number of wei. From that single canonical wei value it derives every other unit by dividing by the appropriate power of ten, keeping a fractional remainder where needed. The hexadecimal form is the wei integer encoded in base 16, the representation Ethereum JSON-RPC expects for value and gas quantities.

Example and tips

Enter 0.000000025 ether and the tool reports 25 gwei, 25,000,000,000 wei, and the hex 0x5d21dba00. Use gwei when thinking about gas prices and ether for balances; reach for wei and hex only when crafting raw transactions or interacting with low-level RPC. Because the converter parses to BigInt, you can safely move between a tiny gas tip and a large balance without losing a single wei of precision.