Options Expected Move Calculator
Before earnings, before an FDA decision, before any binary event, the options market posts its forecast in the form of implied volatility. This calculator turns that volatility into a concrete price range: the expected move, the one-standard-deviation band the market is pricing in, with about 68% probability.
Three modes cover three real workflows. The basic mode converts any implied volatility into a move; the straddle mode backs the move out of actual at-the-money call and put prices and prints the breakevens; the earnings mode quantifies the IV crush waiting on the other side of the report. The tool is pre-filled with a basic example you can verify below.
Options Expected Move Calculator
The 1-sigma price range implied by options, plus straddle and earnings modes
Prefilled with the basic worked example: $150 stock, 30% implied volatility, 30 days.
Expected move
$0.00
Quick Answer
A $150 stock with 30% implied volatility and 30 days to expiration has an expected move of ±$12.90, a $137.10 to $162.90 range with about 68% probability. The calculator above is pre-filled with this exact example. Switch to Straddle Analysis to back the move out of real option prices, or Earnings Move to quantify the IV crush after a report.
How to use the expected move calculator
Pick the mode that matches your question. Each one answers a different version of “how far could this stock go?”
- Basic Expected Move: enter the stock price, the implied volatility from the option chain, and calendar days to expiration. This is the textbook calculation: stock price × IV × √(days/365).
- Straddle Analysis: enter the stock price plus the at-the-money call and put prices for your expiration. The tool adds them into the straddle cost, inverts the formula to find the implied volatility the market is actually charging, and prints the straddle breakevens.
- Earnings Move: enter the stock price, today’s implied volatility, your estimate of implied volatility after the report, and days to earnings. The move comes from the pre-earnings IV; the assessment comes from the crush between the two IVs.
- Read the band, not just the number. The headline is the ± dollar move; the upper and lower range turn it into prices you can place orders around; the volatility assessment tells you what regime the market thinks you are in.
- Remember what 68% means. The band is one standard deviation. Roughly two-thirds of the time the stock should land inside it, which means roughly one-third of the time it lands outside. Size positions for the miss, not just the hit.
The implied volatility driving all three modes is the same input that prices options themselves; the option Greeks calculator breaks down how it interacts with delta, theta and vega.
The formula, and what each mode does with it
The core equation is the market standard: Expected move = stock price × implied volatility × √(days / 365). Implied volatility is annualized, so the square root of time rescales it to your holding period. Because of the square root, time has diminishing returns: doubling the days multiplies the move by about 1.41, not 2.
The three modes differ in where the volatility comes from:
- Basic takes your IV directly. It is the fastest way to sanity-check a broker’s “expected move” figure or to stress-test scenarios.
- Straddle inverts the formula. Since the expected move roughly equals the at-the-money straddle price, the tool recovers the market’s implied volatility as IV = (call + put) / stock × √(365 / days) × 100, then runs the standard calculation with it. The breakevens, stock ± straddle cost, are where a long straddle starts making money.
- Earnings splits volatility into before and after. The move uses the inflated pre-earnings IV, while the assessment measures the crush: (pre − post) / pre. A 50% or larger crush reads as severe, 30% or more as significant, anything less as moderate.
Worked examples: one per mode, all verified in the tool
Basic. $150 stock, 30% IV, 30 days: 150 × 0.30 × √(30/365) = 45 × 0.2867 = ±$12.90. Range: $137.10 to $162.90, an 8.60% move, rated Normal volatility. The tool’s summary reads: “Basic expected move calculation: $150.00 stock for 30-day period at 30% IV. Expected ±$12.90 move (8.6%). Range: $137.10 – $162.90 with 68% probability (1 standard deviation). Moderate volatility expected.”
Straddle. $150 stock, $6.00 call, $5.50 put, 30 days. Straddle cost = $11.50; implied IV = (11.50/150) × √(365/30) × 100 ≈ 26.74%; expected move = ±$11.50, essentially the straddle price itself, which is why traders use the straddle as the shortcut. Breakevens: $138.50 and $161.50.
Earnings. $200 stock, 60% pre-earnings IV, 25% post-earnings IV, 7 days. Expected move = 200 × 0.60 × √(7/365) = ±$16.62, range $183.38 to $216.62. IV crush = (60 − 25)/60 = 58%, rated “Severe IV Crush Expected (58%)”. That crush is the quiet killer of long premium into earnings: even if the stock moves the expected amount, the options can lose value as volatility collapses.
| Scenario | Expected move | Range | Assessment |
|---|---|---|---|
| Basic: $150, 30% IV, 30 days | ±$12.90 | $137.10 – $162.90 | Normal Volatility |
| Basic: $100, 10% IV, 7 days | ±$1.38 | $98.62 – $101.38 | Low Volatility |
| Basic: $50, 75% IV, 365 days | ±$37.50 | $12.50 – $87.50 | Extreme Volatility |
| Straddle: $150, $6 call, $5.50 put, 30 days | ±$11.50 | $138.50 – $161.50 | Normal Volatility (26.74% implied) |
| Earnings: $200, 60%/25% IV, 7 days | ±$16.62 | $183.38 – $216.62 | Severe IV Crush Expected (58%) |
Two honest edge behaviors are worth knowing before you trust the tool blindly. With extreme inputs the band is symmetric and unbounded, so a $1,000,000 stock at 200% IV prints a lower range of −$1,000,000.00: mathematically consistent, economically impossible, and your signal to sanity-check the inputs. And if you enter a post-earnings IV above the pre-earnings IV, the crush goes negative and the tool still labels it “Moderate”, for example “Moderate IV Crush Expected (-17%)”. Both are preserved exactly as the model behaves, and both are disclosed here rather than hidden.
What competing tools get wrong
Six established expected-move resources were checked for mode coverage, IV-crush handling, and empirical honesty.
- SummitOption expected-move research: the rare empirical check, 899 stocks studied. Weekly moves landed inside the expected range 73.9% of the time versus 68.3% theory, and IV fell after 92.8% of 4,397 earnings reports. Strength: real validation. Gap: a research article, not a calculator.
- EarningsWatcher implied moves: live weekly tables of earnings implied moves with implied-versus-actual history going back years. Strength: real market data. Gap: no calculator on the page; the working tools sit behind membership.
- MarketXLS earnings expected-move template: runs two methods, the 85%-of-straddle rule and an ex-earnings variance decomposition that isolates the earnings jump from background volatility. Strength: the most careful earnings math. Gap: an Excel template needing a paid add-in, not a web tool.
- TheOptionPremium expected-move guide: teaches both paths, the straddle shortcut and the IV formula, with a clean $100/30%/30-day example. Strength: practical trading framing. Gap: a blog post with no tool behind it.
- PowerOptions expected move calculator: the strongest tool rival, with full-straddle and 85%-rule methods, probability readouts, IV rank and a screener. Strength: depth. Gap: key features gated behind a free trial, and no IV-crush readout for earnings.
- TradingView monthly expected-move indicator: overlays IV, straddle, historical-volatility and ATR bands on the chart. Strength: visual comparison of implied versus realized. Gap: requires pasting IV by hand and a TradingView account.
- The gap this page fills: three modes on one page where every rival covers one, an explicit IV-crush gauge for earnings (severe at 50%+, significant at 30%+), straddle breakevens printed next to the range, and the empirical caveat stated up front: the band holds about 68% of the time in theory and a bit more in practice, while the misses cluster fatter than a bell curve admits.
For position sizing around these ranges, the option margin calculator estimates what a short-volatility position ties up, and the put-call ratio calculator reads the sentiment backdrop the move is priced into.
Frequently asked questions
The one-standard-deviation price range the options market is pricing in for a stock over a given period. It is derived from implied volatility: multiply the stock price by IV and by the square root of time. About 68% of the time the stock should finish inside the band, which also means about 32% of the time it finishes outside it.
Expected move = stock price × implied volatility × √(days / 365). For a $150 stock at 30% IV with 30 days to expiration: 150 × 0.30 × √(30/365) = ±$12.90. The square root means time has diminishing returns: four times the days only doubles the move.
The at-the-money straddle, call price plus put price for the same strike and expiration, is the market’s dollar vote on the move, and it closely approximates the formula result. This calculator’s straddle mode works backwards from those two prices: it recovers the implied volatility the market is charging, then computes the move and prints the breakevens at stock ± straddle cost.
Before earnings, options price in uncertainty about the report, which inflates implied volatility. Once the numbers are public the uncertainty vanishes and IV collapses, often the next session; that collapse is IV crush. The earnings mode compares your pre- and post-report IV: a 50% or larger drop reads as severe, 30% or more as significant, anything smaller as moderate. Long premium can lose money into earnings even when the stock moves as expected, because the crush eats the option’s value.
The stock prices at which a long at-the-money straddle breaks even at expiration: the stock price plus the straddle cost, and the stock price minus the straddle cost. For the worked example ($150 stock, $11.50 straddle), the breakevens are $138.50 and $161.50. Inside that range the straddle loses money; outside it, it profits.
The formula is symmetric and unbounded: it subtracts the same dollar move it adds, with no floor at zero. With extreme inputs, such as a $1,000,000 stock at 200% IV for a year, the lower range prints −$1,000,000.00. That is mathematically consistent but economically impossible, since a stock cannot fall below zero. Treat an impossible lower bound as a signal to recheck your inputs, not as a tradeable price.
It means the post-earnings IV you entered is higher than the pre-earnings IV, so the “crush” is negative: volatility is expected to expand, not collapse. The tool still labels any crush below 30% as moderate, including negative ones. A negative crush is unusual around earnings but legitimate as a scenario input, for example when a report is expected to raise more questions than it answers.
Roughly in line with theory, with fatter tails. One study of 899 stocks found weekly prices finished inside the expected move 73.9% of the time, a bit above the 68.3% a bell curve predicts, and 80 to 83% for index ETFs. But extreme moves happen more often than the normal distribution admits, about 2.7 times as often beyond three times the expected move. Use the band as a baseline for position sizing and strike selection, never as a guarantee, and never as investment advice.
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References
- Cboe. Cboe European-Style Options Implied Volatility Calculation Methodology (PDF). Accessed October 23, 2026.
- CME Group. Understanding the CVOL Index: Implied Volatility Curves. Accessed October 23, 2026.
- Financial Industry Regulatory Authority. Regulatory Notice 22-08: Options Account Approval and Risk Disclosures. Accessed October 23, 2026.
- The Options Industry Council. Options Basics FAQ. Accessed October 23, 2026.
- The Options Clearing Corporation. Publications: Characteristics and Risks of Standardized Options. Accessed October 23, 2026.
- Cboe. The Options Institute: Learn Options Trading from the Experts. Accessed October 23, 2026.
- CME Group. Options Analytics: Greeks and Implied Volatility Data. Accessed October 23, 2026.
- MDPI, Journal of Risk and Financial Management. BeVIXed: Trading Fear in the Volatility Complex. Accessed October 23, 2026.
- Panathea. White Paper: Volatility Instruments and Strategies (PDF). Accessed October 23, 2026.
- CME Group. Options on Futures: Short-Dated Options and QuikStrike Strategy Tools. Accessed October 23, 2026.