FREE OPTIONS TOOL

Options spread
cost calculator.

Turn a bid-ask quote into a clearer picture of trading friction. No signup. Just the numbers.

Enter your quote

01 / INPUTS

Prices in USD per underlying unit. Minimum nonzero price: $0.000001.

Quoted sell price per unit.
Quoted buy price per unit.
Positive whole contracts.
Often 100. Verify your contract.

Quote inputs stay in this browser. They are not sent or saved.

Your spread, in dollars

02 / RESULTS

Example: 2 contracts × 100 units

Buying at ask vs. midpoint

$20.00

Hypothetical additional purchase cost

Quote midpoint

$1.10Per underlying unit

Spread / midpoint

18.18%Quote width as a percentage

Hypothetical round-trip difference

Buy at ask, then sell at bid
$40.00

Midpoint fills are not guaranteed. Results exclude fees and price movement, and assume the entered prices for the full quantity.

BEHIND THE NUMBERS

Understand the gap
before you trade.

This is quote arithmetic, not a trading recommendation or an estimate of your actual execution.

How the calculator works
  • Midpoint(Bid + Ask) ÷ 2
  • Spread percentage(Ask − Bid) ÷ Midpoint × 100
  • Ask vs. midpoint(Ask − Midpoint) × Contracts × Multiplier
  • Round-trip difference(Ask − Bid) × Contracts × Multiplier

When both prices are zero, spread percentage is undefined and shown as N/A. Quotes may change, and displayed size may not cover your order.

For a worked example and a quote-quality checklist, read the bid-ask spread guide.

KEEP EXPLORING

Put the numbers in context.

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