How Much Theta Decay Per Day Do Options Lose?

The amount of theta decay per day depends on three things: how far the option is from expiration, whether it's at the money, and the implied volatility of the underlying. Here are realistic numbers so you know what to expect.

Theta Values for a $100 Stock (IV ~30%)

| Expiration | ATM Call Theta | OTM Call (0.30 delta) Theta | 7 DTE-$0.12/day-$0.06/day 14 DTE-$0.08/day-$0.04/day 30 DTE-$0.05/day-$0.03/day 60 DTE-$0.04/day-$0.02/day | 90 DTE | -$0.03/day | -$0.015/day |

Per contract (100 shares), multiply by 100. So an ATM call at 7 DTE loses about $12/day. At 30 DTE, it's about $5/day.

Higher-Priced Stocks Have Higher Dollar Theta

Theta scales roughly with stock price. For SPY around $530:

  • ATM call at 7 DTE: roughly -$0.65/day ($65/contract)
  • ATM call at 30 DTE: roughly -$0.28/day ($28/contract)
  • ATM call at 60 DTE: roughly -$0.20/day ($20/contract)

    • For AMZN around $185:

  • ATM call at 7 DTE: roughly -$0.22/day ($22/contract)
  • ATM call at 30 DTE: roughly -$0.10/day ($10/contract)

    • How IV Affects Theta

    Higher implied volatility means more extrinsic value, which means more theta to decay. The same ATM option on two different stocks can have vastly different theta:

    Low IV stock (IV 20%): ATM 30 DTE call theta = -$0.03 High IV stock (IV 60%): ATM 30 DTE call theta = -$0.09

    This is why selling premium on high-IV names is popular. You're collecting three times the daily theta compared to a low-IV equivalent.

    Weekly vs. Monthly Theta Breakdown

    Theta is a daily number, but it compounds over time:

    Example: You buy a 30 DTE SPY $530 call at $7.80. Theta is -$0.28/day initially.

  • Week 1: Loses about $1.80 in time value (theta increases slightly each day)
  • Week 2: Loses about $2.10
  • Week 3: Loses about $2.40
  • Final days: Remaining $1.50 evaporates rapidly

    • After two weeks, you've lost roughly $3.90 of the $7.80 premium to theta alone. That's 50% of your investment gone to time, before any stock movement matters. This is why buying short-dated options is so difficult.

    What This Means for Your Trading

    For option buyers: You need the stock to move approximately theta-per-day in your direction just to break even on time. A $0.28/day theta on SPY means you need SPY to move about $0.55/day in your direction (assuming 0.50 delta) to tread water. That's $2.75/week you're losing to the clock.

    For option sellers: That same $0.28/day is income flowing to you. Selling an ATM SPY strangle at 30 DTE could generate $0.56/day in combined theta ($56/day per strangle).

    For spread traders: Your net theta is what matters. A credit spread has positive theta (the short option decays faster than the long), but the net theta is reduced by the long leg.

    Track your total portfolio theta to understand your daily "rent" (if buying) or "income" (if selling). OptionsPilot's position dashboard shows aggregate theta across all your options positions, making this calculation automatic.