About our bitcoin tools

Bitcoin converter: value = amount of BTC × price of 1 BTC. For USD, EUR, GBP, CAD, CHF, AUD and JPY the price is mempool.space's own. For any other currency it is the US dollar price × that currency's units per dollar, a cross rate.

Satoshi converter: 1 BTC is exactly 100,000,000 satoshis, the smallest unit the Bitcoin protocol records. Satoshis = BTC × 100,000,000, and one satoshi's value = price of 1 BTC ÷ 100,000,000.

Power law and rainbow chart: log10(price) = a + b × log10(days since 3 January 2009), fitted by least squares to every daily close in the history. The corridor is the 5th to 95th percentile of the closes' distance from that line; the rainbow's nine bands are equal steps in log space centred on it.

Retirement calculator: until retirement the price grows by the same factor each month, and each month's purchase buys amount ÷ that month's price. From retirement, a year's spending is sold at the start of each year and the price then moves by the second rate. No fees, tax or inflation.

Fee estimator: fee = rate in sat/vB × virtual size. Virtual size = 10 bytes of overhead (10.5 with segwit) + inputs × input size + outputs × output size, with sizes worked out from the transaction format at 72-byte signatures.

Address checker: legacy addresses carry a 4-byte double SHA-256 checksum (base58check); native segwit addresses carry a 6-character bech32 (BIP 173) or bech32m (BIP 350) checksum. Both are verified in the browser.

Mining calculator: bitcoin a day = your hashrate ÷ network hashrate × blocks a day (86,400 ÷ average block time) × block subsidy. Transaction fees are left out.

Average cost calculator: average price = Σ(BTC bought × price paid) ÷ Σ(BTC bought), a weighted average. Profit = total BTC × today's price − total spent, and the return is profit ÷ total spent. Fees are not included unless you add them to the price you enter.

Price target calculator: value at target = your BTC × target price; multiple = target ÷ today's price; BTC for a goal = goal ÷ price; price for a goal = goal ÷ your BTC. It does arithmetic on the target you enter and predicts nothing.

Savings calculator: monthly amount = income × share; BTC a month = monthly amount ÷ today's price; BTC after N years = BTC a month × 12 × N; satoshis a day = BTC a year × 100,000,000 ÷ 365.25. The price is held at today's level.

Stack sats calculator: BTC still to buy = goal − BTC held; purchases = that ÷ (amount ÷ price), rounded up; days = (purchases − 1) × days per period (1, 7 or 365.25 ÷ 12); cost = purchases × amount. The price is held at today's level.

Bitcoin loan calculator: LTV = loan ÷ (collateral BTC × price). A threshold price = loan ÷ (collateral BTC × the threshold LTV), once for the margin call and once for liquidation. Interest = loan × APR × months ÷ 12, simple interest. Lenders' thresholds differ, so the defaults are examples.

Liquidation calculator: for an isolated-margin linear position, a long is liquidated at entry × (1 − 1 ÷ leverage + maintenance) and a short at entry × (1 + 1 ÷ leverage − maintenance). Margin = size × entry ÷ leverage. Fees and funding are left out, and exchanges tier their maintenance rate by position size.

Drawdown tracker: drawdown = 1 − close ÷ highest close so far. For a buy date, the worst fall = 1 − the lowest later close ÷ the close on the buy date. US dollar daily closes, so intraday lows are not shown.

Pizza Day calculator: value = 10,000 BTC × the price of 1 BTC, and each of the two pizzas is half of that. The table uses the US dollar close on 22 May of each year.

Sats per dollar: sats per unit = 100,000,000 ÷ the price of 1 BTC in that currency, and for an amount, sats = that × the amount. The table uses the US dollar close on each year's last day.

Volatility: realized volatility = the standard deviation of daily log returns, ln(close ÷ previous close), over the window × √365. The percentile is the share of past readings at or below the current one.

Supply: the sum of the block subsidy over every block to the current height, with the subsidy halving from 50 BTC every 210,000 blocks. New coins a day = subsidy × 144, and a future date's supply projects 144 blocks a day.

Rounding: results show whole units from 1,000 up, cents from 1, and three significant digits below 1. Satoshi counts are rounded to a whole satoshi, because the network cannot move a fraction of one.