Stock-to-Flow Ratio Calculator
Stock-to-flow divides the existing stock of an asset by the amount produced in a year. A high ratio means the new supply is a small fraction of what already exists, so production can barely move the price — that is what scarcity means in this framework. Solve the relation S2F = Stock / Flow for any of its three unknowns, or build the annual flow from a source-by-source emission breakdown.
For a commodity, flow is just mine production. For a token it is the sum of everything that adds to supply minus everything permanently removed. Enter each source below in units per year; the table totals them into a net annual flow that you can push straight into the Flow field above. Burns are entered as a positive number and subtracted.
Scarcity here means supply rigidity, not rarity
A diamond is rare but a diamond mine can flood the market; gold is abundant but you cannot meaningfully increase annual production in response to price. S2F measures the second property. A high ratio means the flow is a tiny fraction of the stock, so even a large change in production barely moves total supply. That is what makes a commodity resistant to supply-driven price collapse — not the total amount that exists, but how little of it is newly created each year. Bitcoin's ratio is high not because it is rare but because its issuance is fixed and shrinking on a published schedule.
S2F is just the inverse of annual inflation
Dividing stock by flow gives the same number as dividing 100 by the annual inflation rate. An S2F of 50 is a 2% inflation rate; an S2F of 100 is 1%; an S2F of 1 is 100% inflation. This is the most useful mental translation because it converts an abstract ratio into something directly comparable with monetary aggregates. A currency with 7% annual money-supply growth has an S2F of about 14 — lower than silver, far lower than gold. Framing S2F as inflation makes it immediately clear why the metric is used to argue that some assets are harder money than others.
The ratio drifts upward for a fixed-supply asset
If flow is constant while stock grows, S2F grows without bound. That is the trajectory of a commodity with a fixed annual production cap: Bitcoin's flow is set by the halving schedule, so its stock rises while flow periodically halves, and the ratio ratchets upward in steps. Gold behaves differently — production has grown roughly in line with above-ground stock for decades, so its ratio has hovered near 60–75 rather than climbing. Whether S2F rises over time depends entirely on whether production is growing faster or slower than the accumulated stock.
It is a supply metric and says nothing about demand
S2F is entirely a statement about supply. It has no demand term. Two assets with identical S2F can have completely different prices, and an asset with a very high S2F can still fall 90% — which is exactly what happened to Bitcoin in 2022 despite its ratio being at a record high. The metric was popularised alongside a power-law price model that claimed to derive price from S2F alone, and that model failed badly out of sample. This calculator deliberately does not compute a modelled price, because doing so would present a discredited extrapolation as an output rather than a caveat.
How to Use This Calculator
The tool works at two levels: a three-way solver on S2F = Stock / Flow, and a source-by-source breakdown that builds the annual flow from an emissions schedule.
1. Choose what to solve for
Pick Stock, Flow or S2F from the toggle. The calculator rearranges S2F = Stock / Flow automatically for whichever you choose.
2. Use realistic presets
Presets cover gold, silver, platinum, Bitcoin at several halving epochs, and Ethereum — so you can compare the ratio across genuinely different asset classes.
3. Keep stock and flow in the same unit
Tonnes with tonnes per year, coins with coins per year. If you switch from Bitcoin to gold, change both fields together. The ratio itself is unitless, but a mismatched pair produces a meaningless number.
4. Or build flow from the sources
The composition table below breaks annual new supply into block subsidy, staking issuance, unlocks, other emissions and sidechain minting, then subtracts burns. The net total is the flow term — push it into the calculator with one click.
5. Read the result and verdict
The result card shows the ratio alongside annual inflation, supply doubling time and the implied scarcity class. A colour-coded verdict places the asset from highly inflationary through to extreme scarcity.
6. Switch to Advanced for depth
Advanced mode adds an S2F vs. flow chart, a sensitivity check on a +1% input change, and companion metrics including daily and monthly issuance and the years-to-halving implied by a doubling target.
What This Tool Offers
Built around the scarcity relation S2F = Current Supply / Annual New Supply and its translation into annual inflation.
Flow composition breakdown
Six editable supply sources including a subtractive burn row. The table computes net annual flow in real time and pushes it into the calculator.
Three-way solving
Solve for current supply, annual new supply or the S2F ratio. The calculator rearranges the relation for whichever variable you choose.
True-scale scarcity schematic
Stock and flow drawn to the same scale so the flow bar reads as a sliver, plus a scarcity ruler that converts the ratio into years of production.
Scarcity-class verdict
Every result is classified from highly inflationary through to extreme scarcity, with reference points for silver, gold and Bitcoin built into the bands.
Dual comparison charts
S2F vs. current supply for three flow levels, plus an advanced S2F vs. annual flow chart for three stock levels.
Reference tables
Published S2F ratios for gold, silver, platinum, palladium and Bitcoin at each halving epoch, plus an inflation-to-S2F conversion grid.
Reference Tables & Conversions
A scarcity converter, the inflation equivalence grid, and published ratios by asset.
Scarcity converter
Inflation ↔ S2F Equivalence
Because S2F is the reciprocal of the fractional supply growth rate, every ratio maps directly onto an annual inflation figure.
| S2F | Annual inflation | Supply doubles in | Reference point |
|---|---|---|---|
| 1 | 100.00% | 1.0 year | Every coin in existence is recreated annually |
| 2 | 50.00% | 1.7 years | Extremely inflationary; no monetary asset behaves this way |
| 5 | 20.00% | 3.8 years | Worse than the worst hyperinflations |
| 10 | 10.00% | 7.3 years | Well above any developed-market money supply growth |
| 14 | 7.14% | 10.1 years | Roughly a high-inflation emerging market currency |
| 25 | 4.00% | 17.7 years | Broad money growth in a fast-growing economy |
| 40 | 2.50% | 28.1 years | Near silver's published ratio |
| 50 | 2.00% | 35.0 years | At the top of central-bank inflation targets |
| 72 | 1.39% | 50.2 years | Gold |
| 100 | 1.00% | 69.7 years | Hard money threshold |
| 120 | 0.83% | 83.1 years | Bitcoin, post-2024 halving |
| 250 | 0.40% | 173.6 years | Bitcoin, post-2028 halving (projected) |
Published S2F Ratios by Asset
Approximate figures. Commodity stock estimates vary by source — above-ground gold stock is reasonably well measured, silver far less so, and industrial metals are almost impossible to inventory accurately.
| Asset | Stock | Annual flow | S2F | Notes |
|---|---|---|---|---|
| Palladium | ~1,000 t | ~200 t | ~5 | Thin above-ground stock; mostly consumed industrially |
| Platinum | ~4,000 t | ~180 t | ~22 | Similar profile to palladium but a larger stockpile |
| Silver | ~1,000,000 t | ~25,000 t | ~40 | Widely quoted between 22 and 40 depending on stock estimate |
| Bitcoin (2020–2024) | ~19.0M | 328,500 | ~56 | 6.25 BTC block subsidy era |
| Gold | ~216,000 t | ~3,000 t | ~72 | The benchmark hard asset; ratio has been stable for decades |
| Bitcoin (2024–2028) | ~19.7M | 164,250 | ~120 | 3.125 BTC block subsidy era |
| Ethereum (gross issuance) | ~120M | ~620,000 | ~194 | Gross staking issuance, before burns are netted off |
| Bitcoin (2028–2032) | ~20.3M | 82,125 | ~247 | 1.5625 BTC block subsidy era, projected |
| Bitcoin (2032–2036) | ~20.7M | 41,063 | ~504 | 0.78125 BTC block subsidy era, projected |
Variable Reference
| Symbol | Meaning | Typical range | Units |
|---|---|---|---|
| Stock | Current supply in existence | 10³ – 10¹² | units |
| Flow | Annual new supply | 10⁰ – 10⁹ | units / year |
| S2F | Stock-to-flow ratio | 1 – 500 | dimensionless |
| Inflation | Annual supply growth = Flow / Stock | 0.2% – 100% | % / year |
| Doubling time | ln 2 / ln(1 + 1/S2F) | 1 – 700 | years |
| Gross emissions | Total new supply before burns | — | units / year |
| Burns | Supply permanently removed | — | units / year |
| Net flow | Gross emissions − burns | — | units / year |
What Is the Stock-to-Flow Ratio?
Stock-to-flow compares how much of an asset already exists against how much is created each year. The stock is the entire above-ground or circulating supply; the flow is the annual production. Dividing one by the other gives the number of years of current production that would be required to recreate the existing stock.
It is a supply-side scarcity measure. It says nothing about how useful the asset is, how much demand there is for it, or what it should be worth. What it does say is how resistant the supply is to change: a high ratio means new production is a rounding error against the existing pile, so supply is essentially fixed from year to year.
The Stock-to-Flow Formula
The defining relationship is:
Rearranged to solve for the other two unknowns:
Flow = Stock / S2F
The ratio is exactly the reciprocal of the annual supply growth rate, which is why it is so often translated into an inflation figure:
Supply doubling time (years) = ln 2 / ln(1 + 1 / S2F) ≈ 0.693 × S2F
Daily issuance = Flow / 365
Monthly issuance = Flow / 12
Where flow is composed of several sources, it is a sum rather than a single number:
Stock, Flow and the Meaning of Scarcity
Scarcity in this framework does not mean the asset is rare in absolute terms. Gold is not rare — there are over 200,000 tonnes of it above ground. What makes gold scarce in the monetary sense is that only around 3,000 tonnes are added each year, roughly 1.4% of the existing stock. A sudden doubling of gold production would take decades of effort and would still only shift the ratio modestly. That rigidity is what S2F captures.
Compare that with a hypothetical commodity that has a small above-ground stock and large annual production. If 500 units exist and 500 are produced each year, S2F is 1 and the supply doubles annually. Producers can flood the market whenever the price rises, which caps any rally. The stock-to-flow ratio of 1 describes exactly that vulnerability.
| Property | Low S2F | High S2F |
|---|---|---|
| Annual inflation | High | Low |
| Supply response to price | Fast and large | Slow and small |
| Stock as a share of annual production | Small — flow dominates | Large — stock dominates |
| Typical examples | Agricultural commodities, industrial metals | Gold, silver, Bitcoin |
| Supply-driven price caps | Strong | Weak |
Why the Ratio Rises for Some Assets and Not Others
Whether S2F climbs over time depends on whether production grows faster or slower than the accumulated stock. For most commodities, production and stock grow at roughly similar rates, so the ratio stays in a band. Gold has held near 60–75 for decades because mine output has expanded alongside the above-ground pile.
For an asset with a fixed or declining issuance schedule, the dynamics are different. Bitcoin's flow is set by the block subsidy, which halves roughly every four years, while its stock keeps growing. The result is a ratio that steps upward in a sawtooth pattern — flat between halvings, then a jump when flow is cut in half. Whether that pattern continues indefinitely depends on whether the asset retains value once the subsidy becomes negligible, since at that point the security budget has to come from transaction fees rather than new issuance.
Stock-to-Flow Calculation Examples
S2F = 19,700,000 / 164,250 = 119.94
Stock = 72 × 3,000 = 216,000 units
Flow = 19,700,000 / 247 = 79,757 units/yr
Inflation = 100 / 119.9391 = 0.8338%
Doubling time = ln 2 / ln(1 + 1/119.9391) = 83.13 years
Block subsidy = 3.125 BTC
Blocks per day = 144 → blocks per year = 52,560
Flow = 3.125 × 52,560 = 164,250 BTC/yr
Frequently Asked Questions
There is no universal threshold, but the published figures give useful anchors. Palladium at around 5 and platinum at around 22 sit at the low end for precious metals. Silver is usually quoted between 22 and 40 depending on which stock estimate you use. Gold sits around 72 and has been stable there for decades. Bitcoin has climbed from roughly 25 in 2016 to around 120 after the 2024 halving. Above 100 is generally treated as hard-money territory — an annual inflation rate below 1%. The more useful framing is not whether a number is high in the abstract but where it sits relative to gold and to the prevailing growth rate of money supply.
No. This is the most important caveat about the metric. S2F contains no demand term at all — it is purely a statement about supply. An asset can have an extremely high ratio and still lose 80% of its value, because if demand falls, the supply rigidity that looked like a strength becomes irrelevant. The ratio says supply cannot collapse to meet falling demand, which cuts both ways: it prevents dilution, but it also means the price has to absorb the entire adjustment. Bitcoin fell over 70% in 2022 while its S2F was at a record high.
The stock-to-flow ratio was popularised alongside a power-law model that claimed to derive price directly from S2F, and for several years that model appeared to track Bitcoin closely. It then failed badly out of sample: the model's projections implied prices that were never approached, and the relationship it described broke down. Presenting a modelled price as a calculator output would treat a discredited extrapolation as if it were a derived result, which it is not. S2F is a legitimate supply metric; the price model built on top of it was not. This tool computes the former and explicitly declines to compute the latter.
Burns reduce supply, so they subtract from flow rather than adding to it. Enter gross emissions from each source in the composition table, then enter the annual burn amount in the burn row, which is subtracted automatically. If burns exceed gross emissions the net flow is negative, which means the supply is shrinking — S2F becomes undefined in the usual sense because the stock is contracting rather than growing. A deflationary asset has no meaningful stock-to-flow ratio; what it has is a negative inflation rate, which is a stronger statement than any finite S2F.
Mechanically yes — any asset with a measurable stock and a measurable annual production rate can have an S2F computed. Whether the result is meaningful is another question. Real estate is sometimes given an S2F, but "annual new supply" depends entirely on how you draw the boundary, and buildings are not fungible, so the aggregate number is not comparable to gold's. Agricultural commodities have S2F around 1 because the entire stock is consumed and regrown each year, which correctly signals that they cannot function as stores of value. The metric is most meaningful for assets that are fungible, durable, and have a well-defined above-ground stock.
Because Bitcoin's flow is not a smooth function — it is set by the block subsidy, which halves at fixed block heights roughly every four years. Between halvings the subsidy is constant while the stock grows steadily, so S2F drifts upward along a shallow curve. At each halving the flow drops by 50% overnight, so S2F jumps discontinuously. The 2024 halving took the subsidy from 6.25 to 3.125 BTC and the ratio from roughly 56 to roughly 120. The same step pattern is projected for 2028 and 2032, with each halving producing a progressively larger but less impactful jump as the subsidy becomes a smaller share of total supply.
Mathematically, S2F goes to infinity and annual inflation goes to zero. That is the terminal state of a fixed-supply asset once issuance ends — Bitcoin's last subsidy is scheduled for around 2140. In practice the metric stops being useful well before that point, because the ratio becomes so large that changes in it carry no information: going from 500 to 1,000 tells you nothing new about scarcity. What matters in that regime is not the supply schedule but whether the asset retains demand without any issuance subsidy paying for its security.
Variables
| Symbol | Quantity | Unit |
|---|---|---|
| S2F | Stock-to-flow ratio | |
| Current Supply | Total current circulating supply | coins |
| Annual New Supply | New coins created per year | coins |
What it means
The Stock‑to‑Flow (S2F) ratio is the number of years it would take to produce the current supply at the current annual production rate. A higher S2F indicates greater scarcity. It is widely used in Bitcoin price modelling, with a historical correlation to price. Understanding this helps in assessing the long‑term value of scarce assets like Bitcoin.
Worked example
Stock‑to‑Flow Ratio – Two Detailed Examples
Real‑World| Parameter | Value |
|---|---|
| Current Supply | 19,700,000 |
| Annual New Supply | 328,500 |
| Parameter | Value |
|---|---|
| Supply | 19,700,000 |
| New Supply | 164,250 |
Common mistakes
- Stock‑to‑flow (S2F): Ratio of current supply to annual new supply.
- Current supply: The total circulating supply.
- Annual new supply: The amount mined in a year.
- Higher S2F: Indicates scarcity and is used for Bitcoin price models.
Applications
Stock‑to‑flow (S2F) ratio compares the current supply of an asset to the annual new supply, indicating scarcity. This is used as a valuation model for Bitcoin and other hard‑capped assets. A higher S2F suggests greater scarcity and potential price appreciation. Investors use S2F to gauge the long‑term value proposition. Understanding S2F is popular in Bitcoin analysis.
- Valuation of scarce assets like Bitcoin
- Long‑term price prediction based on scarcity
- Comparing the monetary properties of different assets
- Understanding the impact of supply reduction (halvings)
- Educational understanding of stock‑to‑flow model
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