Research and source selection
Educational explanations use Bitcoin.org, Bitcoin Core and Bitcoin Improvement Proposals where appropriate. Consumer warnings use official regulators or consumer-protection bodies. Service-specific features must be checked against the provider’s current terms for the reader’s country. We avoid unsupported fee rankings.
Current price references
Current calculators request the Coinbase spot-price API in the selected fiat currency. A browser receipt time is labeled “Last fetched”; the API does not supply an exchange trade timestamp. Refreshes occur every minute while visible. A quote older than five minutes is excluded. A failed refresh is disclosed. These are reference prices, not executable offers.
Purchase calculator
Percentage fee is applied to the total budget. Percentage and fixed fees are deducted from that budget and rounded to the currency’s minor unit. Effective buy price = reference price × (1 + entered spread ÷ 100). BTC = (budget − fees) ÷ effective buy price, rounded down to a whole satoshi. A spread is modeled as a markup on the reference price, not another cash fee. Enter zero spread if a manual provider price already includes it. Actual provider formulas may differ.
Historical calculator
The locally hosted daily USD snapshot comes from Blockchain.com Market Price (USD). The provider describes it as an average across major Bitcoin exchanges. We retain positive observations, keyed to the UTC date bucket. Zero and missing observations are unavailable; we do not substitute the next date or interpolate. This is not a guaranteed daily closing or tradable price.
BTC = initial USD amount ÷ historical reference, rounded down to eight decimal places. Reference value = that BTC × the current Coinbase USD reference. Change = (reference value − initial amount) ÷ initial amount × 100. Multiple = reference value ÷ initial amount. The historical and current sources differ in methodology and venue. That difference affects results.
The snapshot starts August 18, 2010. Early trading was thin, access was limited, and large modeled purchases may have been impossible at the quoted price. Results assume immediate access at the reference, uninterrupted ownership and recoverable keys. Fees, spreads, taxes, slippage and custody costs are excluded. Dates outside the snapshot or without a valid observation cannot calculate. The tool shows the snapshot range and fetch time. Refresh the snapshot using the included maintenance script before publishing new dates.
Future scenario calculator
BTC = entered USD amount ÷ current Coinbase USD reference, rounded down to whole satoshis. Scenario value = BTC × the price chosen by the reader. Gain/loss = scenario value − initial amount. Percentage change = gain/loss ÷ initial amount × 100. A zero scenario price is valid and models complete loss. Fees, taxes and other costs are excluded. No probability or forecast is implied.
Shared calculator links
Share links contain the amount and selected date or scenario in the URL fragment. Anyone with the link can read these entries. Opening a shared link recalculates using the price then available; it is not a frozen valuation. The canonical page address remains the same.
Network estimates
The halving tool uses mempool.space’s public API for the current block height. Remaining blocks to 1,050,000 are multiplied by ten minutes. It is an estimate, not a scheduled calendar time. Missing or old data does not create a fallback countdown.
Comparison methodology
We compare payment and custody categories against the same questions: availability, total cash charged, Bitcoin delivered, settlement, withdrawal access, key control and recovery obligations. We do not rank exchanges without current evidence for a specified jurisdiction, account type and order size. Official platform links are examples, not endorsements. Payment, when introduced, must not determine editorial rankings and must be disclosed.
Corrections policy
Report a factual or calculation issue to hello@buybitcoinstoday.com with the page, steps and supporting source. We review the report, correct verified errors and add a dated note for material changes. An unresolved claim may be removed or qualified while it is checked. No correction history is invented to imply a longer publication record.