Record the amount of BTC
Use the balance shown by a source you trust and retain enough decimal places for the amount you actually hold. Bitcoin can be represented in BTC or satoshis; 1 BTC is 100,000,000 satoshis. Convert units carefully if your own record uses satoshis.
When BTC is spread across a hardware wallet, an exchange and another address, reconcile each balance before combining them. Transfers between your own locations change where BTC is held, but do not by themselves create more BTC.
Add cost details you can support
For each buy, retain the quantity, price, date and fees from your records. A single average price can be a convenient summary, but it does not replace a transaction history or determine the tax treatment of a disposal. Local tax rules may require a specific accounting method.
Use a reference price consistently
Multiply BTC quantity by a price expressed in the same fiat currency to get a simple value estimate. The result changes with the price source and time. A reference quote is not a promise of the amount you could receive after spread, fees or market movement.
Common questions
Can I track Bitcoin from a cold wallet?
Yes. Enter the balance manually. You do not need to connect the wallet or provide a public address to calculate a value from a quantity.