Bull Put Spread Calculator
A bull put spread sells a put and buys a lower one, collecting a credit that is your maximum profit while the long leg caps the downside. Max loss is the strike width minus the credit. Enter both legs to see the turn.
The arithmetic
The default sells the $95 put for $2.20 and buys the $85 put for $0.70 — a $1.50 net credit, $150 per spread.
- Max profit = the credit, $150, at any price at or above $95.
- Max loss = (10 − 1.50) × 100 = $850, at any price at or below $85.
- Breakeven = short strike − credit = $93.50.
The same shape as a bear call spread, pointed the other way
This is the bullish mirror of the bear call spread: a high probability of a small gain, a low probability of a loss several times larger. It profits if the stock rises, drifts sideways, or falls modestly — anything above $93.50 at expiration.
Against a cash-secured put, the difference is what the long leg does to your worst day. The cash-secured put risks $9,280 and takes in $220. This risks $850 and takes in $150. You give up a third of the premium to remove 90% of the maximum loss — and unlike the cash-secured version, you never end up owning shares you now have to manage.
Assignment risk is real but manageable
If the stock falls below your short strike near expiration, that put can be assigned and you will be long 100 shares per contract. The long $85 put is still yours and still protects, but the position now ties up real capital and behaves differently. Traders usually close a credit spread that has gone in the money rather than let it run into expiration for exactly this reason.
Why this is the most over-sold structure in options
A high win rate is unusually pleasant to experience. Ten winners in a row on a 5.7:1 risk/reward is not evidence of an edge — it is the expected shape of a position that wins 85% of the time, and it will be followed by the loss that pays for them. The only way to know whether a put-selling programme is working is to record every position before the fact and check the full distribution afterwards, not to remember the winners.
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
A credit spread is trivial to price. 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 breakeven on a bull put spread?
The short put strike minus the net credit per share. Selling the $95 put for a $1.50 net credit breaks even at $93.50.
What is the maximum loss on a bull put spread?
The strike width minus the net credit, times 100. A $95/$85 spread taken in for $1.50 risks $850 per spread.
Bull put spread or cash-secured put?
The spread risks far less and ties up far less capital, for a smaller credit. The cash-secured put pays more and leaves you owning the shares if assigned — which is only good if you wanted them.
What happens if I'm assigned on the short put?
You buy 100 shares per contract at the short strike. Your long put still caps the downside, but the position now uses real capital. Most traders close the spread before expiration instead.