Options breakeven & charges calculator

What an option's breakeven is, in one paragraph

An option's breakeven is the underlying price at which the position neither makes nor loses money: the strike plus the premium for a call, the strike minus the premium for a put. Brokerage, STT, exchange and SEBI fees, stamp duty and GST shift that level against the holder by the charge per unit.

How it is calculated

Two numbers are produced. The first is the textbook identity. The second replaces the premium in that identity with the premium the position would have to be closed at to come out level — which is higher than the premium paid on a bought option, and lower than the premium received on a sold one. Because STT is a percentage of the sale value, the charge depends on the closing premium and the closing premium depends on the charge, so the calculator solves the two together rather than adding a fixed estimate.

Worked example: one NIFTY 25000 call

Bought at a premium of ₹120, one lot of 65 units, brokerage ₹20 per order, on 4 September 2026. The premium outlay is 120 × 65 = ₹7,800, and the textbook breakeven is 25,000 + 120 = 25,120. The lot size is filled in from the published contract specification and stays editable.

₹61.89 spread over 65 units is ₹0.952 per unit, so the option has to be worth ₹120.96 to come out level (rounded up to the next paise, because premiums trade in paise). Put that back into the identity and the breakeven is 25,000 + 120.96 = 25,120.96 — 0.96 index points further away than the textbook number. Sell the same call instead and the arithmetic mirrors: the position can only be bought back at ₹119.04 or less, so its breakeven sits at 25,119.04 rather than 25,120.

Edge cases that trip people up

Letting an option expire is not the same cost as closing it

This calculator prices a square-off: two orders on the exchange. An in-the-money option left to expire is settled by exercise or assignment, and STT on an exercised option is charged on the intrinsic value rather than on the premium. That is a completely different base, and on a deep in-the-money contract it can dwarf every other line above.

Flat brokerage is the whole story on small positions

On one lot, ₹40 of brokerage is roughly two-thirds of the ₹61.89 total. Ten lots of the same contract shift the breakeven by about 0.30 points instead of 0.96, because the flat fee is spread over 650 units. The percentage charges do not shrink, so the shift falls toward a floor — it never reaches zero, even with a zero-brokerage plan, which still shifts the example by 0.23 points.

A sold option can have no breakeven at all

If the premium received is smaller than the round-trip charges, no closing price makes the position level. The calculator says so rather than printing a number.

Breakeven is an expiry identity, not a live mark-to-market

Before expiry an option also carries time value, so the position's value at a given underlying level is not the payoff diagram. The breakeven here answers “where does the payoff cross zero at expiry?”, not “what is this contract worth right now?”

Lot sizes are revised, and SENSEX is a different exchange

Exchanges change index-option lot sizes from time to time. The lot size is filled in from the published circular for the instrument and trade date entered, and stays editable — a contract opened before a revision can still be running on the previous lot, and the calculator says so when that applies. SENSEX options trade on BSE, which publishes its own transaction charge, so switching instrument changes that line too.

Your contract note is the final word

Percentage-based brokerage plans, depository charges and any broker-specific fees are not modelled. The statutory and exchange charges are the published ones for the trade date entered.

Where this sits in the NISM Series VIII syllabus

Option payoffs, breakeven points and moneyness are covered in the option-payoffs chapter of the NISM Series VIII: Equity Derivatives certification, which is the mandatory certification for approved users and sales personnel of trading members in the equity-derivatives segment. The syllabus states the breakeven identities for long and short calls and puts; the arithmetic on this page is those identities applied to the Indian charge structure. This page is educational material, not NISM study material, and is not affiliated with or endorsed by NISM.