Controlled Supply Rule - Total of 21M BTC

This section describes what is the Bitcoin Controlled Supply Rule - There will be only 21M BTC in total.

One important Bitcoin Consensus Rule is the Controlled Supply Rule: Total supply of Bitcoins is controlled to a fixed number of 21 million Bitcoins.

The 21-million-Bitcoin supply limit is set by the Bitcoin founder, Satoshi Nakamoto, who did not give any explanations.

One possible reason is that 21 million is close to the maximum capacity of a 64-bit floating point number in the smallest unit of Bitcoin, 1 Satoshi = 0.00000001 BTC.

In other words, if the total Bitcoin supply is 21,000,000.00000000, we safely use 64-bit floating point number format to record and calculate any Bitcoin amount in the range of 0.00000001 BTC and 20,999,999.99999999 BTC. Overflow or underflow will never happen.

Last update: 2018.

Table of Contents

 About This Book

 Introduction of Bitcoin

 Bitcoin Blockchain

 Bitcoin Wallet

 Bitcoin Core

 Bitcoin Transaction

 Bitcoin-Qt - Bitcoin Core GUI

 Bitcoin Mining

Bitcoin Consensus Rules

 What Are Bitcoin Consensus Rules

Controlled Supply Rule - Total of 21M BTC

 Mining Reward Rule - Start with 50 BTC

 Proof of Work Rule - Find a Small Hash Value

 Bitcoin Block Data Structure

 Bitcoin Transaction Data Structure

 blockexplorer.com API

 Copay - Bitcoin Wallet

 References

 PDF Printing Version