Fair value = 10-16.493 × (days)5.688,
floor = fair × 0.398 (−2σ),
ceiling = fair × 2.512 (+2σ), σ = 0.2.
The model is computed in USD. AUD figures use the live USD→AUD rate.
The Power Law is a theoretical model, not investment advice. The floor has
historically held except briefly during the March 2020 crash.
About the CAGR figures:
Model CAGR (line growth): how fast the model's own
lines rise between the reference date and the projected year. Fair value and
floor share this rate exactly, because the floor is a fixed fraction of fair
value (≈0.40, the −2σ band) and that multiplier cancels in the
ratio. It's currency-independent.
Return: buy now → fair value, the annualised
return if you bought at today's live market price and the price landed on the
projected year's fair value line.
Return: buy now → floor, the same, but landing on
the projected floor instead, a conservative, worst-case-ish
scenario. This can be negative if today's price already sits above the future
floor. Both "buy now" figures start from today and run to the target date.
This website is inspired by @Giovann35084111's post on reddit.
Build the "Bitcoin Power Law Floor Calculator" β a compact, card-style calculator page that computes the model's floor / fair value / ceiling for any date, compares them to the live price, and projects them to a future year. Server-rendered (PHP) with live client-side refresh of the price-dependent figures. Output one self-contained page. ββ STYLE ββ Dark theme, bitcoin-orange accent, but simpler than the editorial pages: a single centered card (max-width ~480px) on a dark background (#0f1115), system-ui font. Card: bg #1a1d24, 1px border #2a2e37, rounded, padded. Heading "π Bitcoin Power Law Floor". Form controls full-width (date input, selects) with a prominent orange "Calculate" button. Result "rows" are flex space-between (label left, value right) with thin dividers; floor value in bold orange, ceiling in red, positive %s green / negative %s red. Include the shared sticky nav (brand + page links; hamburger on mobile, hide on scroll-down) above the card. ββ MODEL ββ Genesis 2009-01-03. fairValue = 10^-16.493 Γ days^5.688; floor = fair Γ 0.398 (β2Ο); ceiling = fair Γ 2.512 (+2Ο). Money formatted with thousands separators. Currency USD or AUD; the model is computed in USD and AUD figures use a live USDβAUD rate derived from the BTC price quoted in both currencies (so it's internally consistent). Live BTC spot fetched server-side (Coinbase primary, CoinGecko fallback, cached ~60s). ββ FORM (GET) ββ β’ Reference date (date input, default today, min 2009-01-04). β’ Project to year (select: reference year +1 β¦ +15, default +2). β’ Currency (USD / AUD). Submit reloads with query params. ββ RESULTS (for the reference date) ββ β’ Current BTC price (live, in selected currency); if AUD also show the USDβAUD rate. β’ Days since genesis. β’ Ceiling (euphoria), Fair value, Floor (support) β model values in selected currency. β’ Price vs floor and Price vs fair value, as signed % (green/red). β’ If the live price can't be fetched, show a friendly note that the model values are still valid. ββ PROJECTION (to the chosen year; same month/day, guarding Feb 29) ββ β’ <year> ceiling / fair value / floor. β’ Model CAGR (line growth) β the annualised growth of the model's own lines between the reference date and the target year (floor and fair share it exactly since the multiplier cancels; currency-independent). β’ Return: buy now β <year> fair value, and buy now β <year> floor β annualised return from today's live price to each projected line (can be negative; both run from today to the target). ββ LIVE AUTO-REFRESH ββ Poll the live spot every 60s via a small JSON endpoint and update IN PLACE only the price-dependent figures (current price, USDβAUD rate, price-vs-floor/fair, the two buy-now CAGRs) β the date-driven model values stay fixed. Show a "live Β· $β¦ Β· updated Ns ago" badge under the Calculate button. ββ COPY / SEO ββ A footnote stating the formula (10^-16.493 Γ days^5.688, floor Γ0.398/β2Ο, ceiling Γ2.512/+2Ο) and that it's a model, not advice (the floor has held except briefly in March 2020), plus an explainer of the CAGR figures and a small credit line to Giovanni Santostasi. SEO: title "Bitcoin Power Law Floor Calculator"; meta description; canonical; OG+Twitter; π favicon; JSON-LD WebApplication (FinanceApplication, free).