eth_getBalance

Returns the balance of the account of a given address.

PARAMETERS

Address - (required) A 20-byte address to check the balance of.

Block Number - (optional) An integer block number, or the string "latest", "earliest", or "pending" as described in the default block parameter.

REQUEST

{
    "jsonrpc":"2.0",
    "method":"eth_getBalance",
    "params":[
        "0x871f1181AA63c988325539cF4b502E092595B50E",
        "latest"
    ],
    "id":0
}

RESPONSE

Result - A hex value of the current ETH balance for the given address, measured in wei.

{
    "jsonrpc": "2.0",
    "id": 0,
    "result": "0x31aa2017de8e981"
}

Converting eth_getBalance response into ETH

To convert the hex string response, measured in Wei to a decimal value measured in ETH we need to complete two steps:

Convert the hex response into decimal (Wei).
Convert the Wei decimal into ETH decimal (10^18 wei = 1 eth).

Depending on what library or language you are using, there are several options here.

# conversion from hex string to decimal
dec = int("hex strong response",16)

# conversion from Wei to to ETH
ethBalance = dec/(10**18)