--- title: "Choppiness Index (CHOP): Formula" description: "The Choppiness Index compares the sum of true range over a lookback with the high-low range of the same window, then scales the result from roughly 0 to..." canonical: https://www.getswoopr.com/indicators/trend/choppiness-index/ source: "Swoopr Investment: https://www.getswoopr.com" --- ## Direct Answer > Choppiness Index (CHOP) is a bounded measure comparing cumulative true range with the high-low range over a lookback to estimate whether price action is choppy or directional. A higher reading generally means price has traveled a lot inside a relatively contained range, consistent with choppier conditions; a lower reading generally means price movement is more directional relative to the total range traveled. The main limitation is that thresholds are conventions and the index does not supply trend direction. # Choppiness Index (CHOP): Formula, Meaning, Signals, Examples and How to Use It ## How Is Choppiness Index Calculated? The Choppiness Index compares the sum of true range over a lookback with the high-low range of the same window, then scales the result from roughly 0 to 100. High values mean price covered a lot of ground inside a narrow range, and low values mean it moved in one direction. **Formula:** `CHOP = 100 * log10(sum of TR over n / (highest high over n - lowest low over n)) / log10(n)` **Inputs:** - Bar high, low and prior close (to compute true range, TR) - Lookback n (14 is commonly used) - Highest high and lowest low over the same n bars **Worked example.** If 14 bars have true ranges summing to 60 while the window's high-low range is 20, CHOP is 41.6. The inputs are illustrative numbers, not market data. **Reading it.** Readings above 61.8 are widely cited as a choppy, range-bound market and readings below 38.2 as a directional one. Values between those two reference zones are treated as indeterminate. **Limits.** The 61.8 and 38.2 zones are conventions, not statistical thresholds, and the index gives no direction. It is also slow to react at the start of a new trend, because the earlier choppy bars remain in the sum. ## Indicator snapshot | Attribute | Value | | --- | --- | | Category | Trend | | Creator / origin | Commonly attributed to E.W. Dreiss | | Common settings | 14 periods common; 61.8 and 38.2 are widely cited reference zones | | Primary purpose | Describe trend direction, persistence, strength, or a smoothed price reference. | | Main limitation | Thresholds are conventions and the index does not supply trend direction. | ## What is Choppiness Index? Choppiness Index is a bounded measure comparing cumulative true range with the high-low range over a lookback to estimate whether price action is choppy or directional. It is a transformation of market data, not an independent forecast. Its value comes from making one market property measurable and repeatable so the same rule can be compared through time or across instruments when the input convention stays fixed. This profile is separate from any trading strategy. It explains what the measure does, how it is calculated, what its readings mean, where it fails, and what other evidence can complement it. Entry, exit, position sizing and portfolio construction belong to strategy or risk-management content. ## Formula **CHOP = 100 × log10(ΣTRN / (HighestHighN − LowestLow_N)) / log10(N)** ### Calculation requirements 1. Define the asset, timeframe, session and data source before calculation. 2. State lookback, smoothing, reset and initialization rules. 3. Define behavior for missing values, zero denominators and warm-up periods. 4. Reproduce a worked example from raw inputs. 5. Compare the result with an independent implementation before publication. ## How to interpret it A higher reading generally means **price has traveled a lot inside a relatively contained range, consistent with choppier conditions**. A lower reading generally means **price movement is more directional relative to the total range traveled**. That is a description of the selected inputs, not a promise about what price will do next. Strong readings can persist, reverse, or become irrelevant when the market regime changes. The neutral zone should be defined by the indicator’s job rather than a generic red/green treatment. Direction-neutral measures should never be visually labeled bullish solely because the number is high. ## Settings and parameter sensitivity A common reference is **14 periods common; 61.8 and 38.2 are widely cited reference zones**. Defaults are conventions, not universal optima. Shorter windows usually respond faster and create more state changes; longer windows smooth more history and react later. When multiple platform conventions exist, publish the exact one Swoopr uses and identify important alternatives. ## Worked hypothetical example Take a liquid instrument and compute Choppiness Index using the documented convention. If the reading moves materially, trace the change back to its raw inputs before assigning meaning. Then compare the reading with one independent information family such as volume, volatility, benchmark-relative performance or price structure. Finally, define what observation would invalidate the interpretation. This prevents the indicator from being treated as a standalone prediction engine. ## Strengths - Reproducible once the exact calculation is fixed. - Suitable for screening, charting, research and comparative analysis. - Forces the analyst to convert vague impressions into explicit rules. - Can be evaluated against a simpler baseline and across regimes. ## Weaknesses and false signals - Thresholds are conventions and the index does not supply trend direction. - Parameter selection can materially change signal timing. - Platform conventions may differ even when the indicator name is the same. - Correlated indicators can create false confidence rather than independent confirmation. - Backtests can be overstated by look-ahead bias, survivorship bias, unrealistic fills and omitted costs. ## Combining Choppiness Index with other indicators Prefer a second measure that answers a different question. Related entities include Aroon, Average Directional Index, Exponential Moving Average, Ichimoku Cloud, MACD, Parabolic SAR. Before calling two signals “confirmation,” test how often they disagree and whether the second measure changes out-of-sample decisions after costs. ## When not to use it Do not use Choppiness Index as a standalone buy/sell instruction or as a substitute for liquidity checks, risk sizing and execution planning. Avoid publishing optimized settings without a clearly defined universe, timeframe, cost model and validation period. Provider-defined indexes or metrics must use the provider’s disclosed methodology and licensing rules. ## Practical checklist - [ ] Exact question defined - [ ] Data source/session fixed - [ ] Formula and parameters documented - [ ] Independent calculation reproduced - [ ] Regime identified - [ ] Redundant indicators removed - [ ] Invalidation condition written - [ ] Costs and execution assumptions included where relevant ## Frequently asked questions ### Is Choppiness Index a buy or sell signal? No. It is an analytical measure. A decision still needs a hypothesis, trigger, invalidation rule, size and exit process. ### What is the best setting? There is no universal best setting. Start from the common convention (14 periods common; 61.8 and 38.2 are widely cited reference zones), test nearby values, and prefer stable parameter regions over a single historical winner. ### Can it be used by itself? It can describe its specific market property, but a complete decision usually needs additional context from another information family. ### Why can the reading differ between platforms? Data feeds, session rules, smoothing, initialization, lookback and provider methodology can all differ. Check the exact convention a given platform uses. ### Does it work on every timeframe? The formula may transfer, but behavior changes with timeframe, liquidity, volatility and execution costs. Validate the exact use case. ### How should it be backtested? Write rules before testing, use point-in-time data, include realistic costs, reserve an out-of-sample period, break results out by regime and compare with a simpler baseline. ## Choose your next step ### Apply - [Choppiness Index Explained](https://www.getswoopr.com/learn/technical-analysis/indicators/choppiness-index/) Step-by-step use, worked examples and the mistakes to avoid ## Related Swoopr content - Parent hub: [Trend Indicators](https://www.getswoopr.com/indicators/trend/) - Related guide: [Choppiness Index Explained](https://www.getswoopr.com/learn/technical-analysis/indicators/choppiness-index/) - Related indicators: Aroon, Average Directional Index, Exponential Moving Average, Ichimoku Cloud, MACD, Parabolic SAR ## Sources and further reading - [TA-Lib Functions](https://ta-lib.org/functions/) - [TradingView built-in indicator list](https://www.tradingview.com/charting-library-docs/latest/ui_elements/indicators/Indicators-List/) ## Editorial note Educational content only. Do not imply guaranteed prediction, accuracy or outperformance. Any provider-specific methodology must be labeled as such and rechecked when the provider changes its methodology. ## Frequently Asked Questions Is Choppiness Index a buy or sell signal? No. Readings above 61.8 are widely cited as a choppy, range-bound market and readings below 38.2 as a directional one. The 61.8 and 38.2 zones are conventions, not statistical thresholds, and the index gives no direction. A trade built on it still needs a trigger, an invalidation rule, a position size and realistic execution assumptions. What is the best setting for Choppiness Index? Choppiness Index takes these inputs: bar high, low and prior close (to compute true range, TR); lookback n (14 is commonly used); highest high and lowest low over the same n bars. There is no universal best setting for the tunable ones, so test them across instruments, regimes and out-of-sample periods and favor stable parameter regions over one historical winner. Can Choppiness Index be used by itself? The 61.8 and 38.2 zones are conventions, not statistical thresholds, and the index gives no direction. It is also slow to react at the start of a new trend, because the earlier choppy bars remain in the sum. For that reason it is read next to measures of direction, participation, valuation, liquidity and risk, not alone. Does Choppiness Index work on every timeframe? The calculation (CHOP = 100 * log10(sum of TR over n / (highest high over n - lowest low over n)) / log10(n)) can be run on any bar size, but behavior is not portable: a reading on a five-minute chart describes a very different market window from the same reading on a daily chart. Validate the exact timeframe before relying on it. Why does Choppiness Index give false signals? A single large bar inflates both the true range sum and the high-low range, so the ratio can shift sharply when it enters or leaves the window. A sharp trend that follows a long consolidation keeps the reading high for several bars, so the index can still say choppy while a move is already underway. Lag, noise and regime changes add to this, because market participants react to new information after the reading is calculated. How should Choppiness Index be backtested? Rebuild Choppiness Index from bar high, low and prior close (to compute true range, TR) using point-in-time data, write the rules before testing, include delisted securities where relevant, model realistic fills and costs, reserve a validation sample and compare with a simpler baseline. S Swoopr Editorial Team The Swoopr Editorial Team produces independent investment education, research, and tools for understanding markets, evaluating opportunities, and managing risk. All content is educational only and does not constitute personalized investment advice. See our [editorial policy](https://www.getswoopr.com/legal/editorial-policy/) and [corrections policy](https://www.getswoopr.com/legal/corrections-policy/).