How to Use the Opposite‑Side Hedge & ROI Calculator

What this tool does

• Sizes a hedge bet on the opposite side to equalize profit across outcomes.
• Shows hedge stake, guaranteed profit or loss, ROI, and PnL by outcome.
• Lets you save multiple plays locally in your browser and manage them in a table.

Before you start

• You need two prices:
  1. Your initial bet’s odds and stake.
  2. The current live odds on the opposite side.
• The tool accepts American, Decimal, or Fractional odds.

Step 1 — Enter your initial bet

• Stake (your bet size): Type how much you wagered (example: 100).
• Odds: Enter your original odds (examples: -160, 1.625, or 5/8).
• Format: Choose American, Decimal, or Fractional to match what you typed.
  As you type, you’ll see:
• Decimal (your side): Your odds converted to decimal for clarity.
• Net if your side wins: Profit from your original bet alone, excluding stake.

Step 2 — Enter the live opposite price

• Opposite price (live): Type the current odds on the other side of your original bet (examples: +260, 3.60, 13/5).
• Format: Choose the odds format you used above.
  The calculator then:
• Converts the opposite price to Decimal and American.
• Computes Hedge Stake (to place): the amount to bet now on the opposite side to equalize profit.
• Shows Total Stake: initial stake + hedge stake.
• Shows Guaranteed Profit (both outcomes) and Guaranteed ROI: what you lock in regardless of who wins.
• Shows PnL if Your Side Wins and PnL if Opposite Wins: both will match the guaranteed profit for an equalized hedge.

Tip: Want a partial hedge (not fully equalized)?

• Reduce the hedge stake manually at your sportsbook to keep more upside and some downside. The app currently displays the equalized hedge size; if you hedge less, your outcome PnLs won’t be equal—by design.

Saving and managing multiple plays

Create a play

• Title: Give your play a short name (e.g., “EV Play 1” or “Heat @ Knicks 2H”).
• Click Save Play. Your play appears in the Saved Plays table.

Start a new entry

• Click New/Clear to reset the input fields without touching your saved table.

Use the Saved Plays table
The table shows:

• Title, Stake, Your Odds, Opposite Odds, Hedge Stake, Profit, ROI, and Actions.
  Actions per row:
• Load: Fills the calculator with that play so you can re-check or adjust.
• Duplicate: Makes a copy you can rename and tweak.
• Delete: Removes the play from your browser.

Where your data is stored

• Everything saves locally in your browser via localStorage.
• Clearing site data, using private browsing, or switching devices/browsers will remove saved plays.

Understanding the formulas

• Convert American to Decimal:
  • Negative x: d = 1 + 100/|x|
  • Positive x: d = 1 + x/100
• Hedge stake to equalize profit: sB = sA × dA / dB
• Profit if your side wins: sA(dA − 1) − sB
• Profit if opposite wins: sB(dB − 1) − sA
• Guaranteed ROI: P / (sA + sB), where P is the profit amount (can be negative if you lock a loss)

When to hedge vs. let it ride

• The equalized hedge locks a certain profit or loss and eliminates outcome risk.
• A quick decision rule: estimate your live win probability (use market odds as a proxy). If the expected value of continuing is lower than the guaranteed outcome, hedge. Otherwise, consider riding or using a partial hedge to balance EV and variance.

Common inputs and examples

• Example 1: You bet $50 at +120. Live opposite is −130.
  • Enter 50 and +120 (American), then −130 (American).
  • The tool outputs the hedge stake and the guaranteed result if you place it now.
• Example 2: You bet $100 at 2.40 (Decimal). Live opposite is 1.65 (Decimal).
  • Select Decimal for both entries and input the prices.

Troubleshooting

• “—” output: One or more inputs are missing or invalid. Check that odds are valid and greater than 1.00 in Decimal terms.
• Headings or text look off: Your site’s theme may override colors. If needed, ensure headings inside the widget use the app’s color variable “–text.”

Feature ideas or help

• Want export/import, CSV download, or partial-hedge targeting? Ask, and we can extend the tool to include:
  • Export/Import saved plays as JSON or CSV.
  • A slider to pick partial hedge and see skewed outcomes and ROI.
  • De‑vigging from both sides’ live odds to estimate fair probabilities and EV.