Bear Put Spread Calculator
A bear put spread buys a put and sells a lower one, cutting the cost of a long put in exchange for a capped gain. Max loss is the net debit; max profit is the strike width minus that debit. Enter both legs to see it.
The arithmetic
The default buys the $100 put for $3.50 and sells the $90 put for $1.10 — a net debit of $2.40, or $240.
- Max loss = the debit, $240, at any price at or above $100.
- Max profit = (10 − 2.40) × 100 = $760, at any price at or below $90.
- Breakeven = higher strike − net debit = $97.60.
The structural case for spreading a bearish trade
Downside options are expensive. Volatility skew means the put you want to buy prices at a higher implied volatility than the equivalent call, and a plain long put makes you pay all of it. Selling a lower put recovers part of that cost — and because the lower strike is even further down the skew, it is often proportionally rich to sell.
Compare directly on this page: the plain $100 put costs $350 and breaks even at $96.50. Spreading it to $90 cuts the cost to $240 and moves breakeven up to $97.60. Cheaper and easier to win, with the gain capped below $90.
Sizing the width to the thesis
The short strike should sit at the level your bearish thesis actually targets, not at whatever strike makes the debit look small. If you think a stock retraces to support at $92, a $100/$90 spread captures nearly all of that move. If you think it breaks and keeps going, spreading it at $90 sells off exactly the part of the move you were trying to catch.
Both legs decay, and that is the point
A long put loses time value every day. In a debit spread, the short put you sold is also losing time value, in your favour, which softens the bleed while you wait for the move. It does not eliminate it — a debit spread on a stock that sits still still loses money — but it loses more slowly than the outright put.
Where the 100x multiplier comes from
Product specification, not convention: OCC defines a standard equity option as covering 100 shares, premium quoted in points where one point is $100[1] — so a $1.85 premium costs $185, and every payoff here applies that multiplier to the leg structure.
One exception is worth knowing about: adjusted contracts, covered on the options profit calculator.
Calculating it is the easy half
Two strikes and two premiums is the whole calculation. The payoff is arithmetic — anyone can run it. What it cannot show is whether you believed the trade when you put it on, or are describing a winner picked out of a month of noise.
That is the gap kappi closes: the position committed before the fact, sealed and timestamped on a log nobody can edit afterwards. A screenshot of this chart proves you can use a calculator; a sealed commit proves you took the trade. $15/month, no free tier.
Sources
Frequently asked questions
What is the maximum profit on a bear put spread?
The strike width minus the net debit, times 100 per spread. A $100/$90 spread costing $2.40 nets a maximum of $760.
What is the breakeven on a bear put spread?
The long put strike minus the net debit per share. Buying the $100 put for a $2.40 net debit breaks even at $97.60.
Why sell the lower put instead of just buying one put?
It cuts the cost and improves the breakeven, which matters because downside puts price at elevated implied volatility. The cost is that gains stop at the lower strike.
When is a plain long put better?
When you expect a large decline. The spread sells away everything below the short strike, which is exactly the part of a crash you wanted to own.