Fan Football
Spread Lab.

Projected Team A margin = (A offense + A defense + A special teams) − (B offense + B defense + B special teams) + home-field effect + all game adjustments. A positive margin favors A; a negative margin favors B. Team A's displayed spread is the negative of that margin, rounded to the nearest half point. Quarter-point rounding ties go away from zero. Team B receives the opposite spread.

This is an original, transparent fan worksheet, version 1.0. It is not a trained forecasting model or ESPN's Football Power Index. Every point value is manually supplied. NFL home advantage starts at 2 points and college at 3 as editable examples, not measured league averages. No claim of prediction accuracy is made.

Offense reflects scoring efficiency, quarterback play, blocking, and ball security. Defense reflects the ability to prevent points, stop efficient plays, and pressure the passer. Special teams covers kicking, punting, returns, and field position. Use positive numbers for better units and negative numbers for weaker units. Do not enter raw points allowed as a defensive rating.

Adjust for schedule strength before comparing teams. An average baseline must mean the same thing for both teams. Do not mix NFL and college ratings or unrelated college divisions and conferences without adjusting the reference level. If your source gives one overall power rating, enter it once as explained above.

Home field can reflect crowd noise, familiarity, travel, and location. Neutral-site games receive zero automatic home advantage. Enter any crowd imbalance separately only if justified. The quarterback adjustment measures a change from the player assumed in the baseline to the expected starter. Other injuries, suspensions, and opt-outs belong in the separate non-quarterback field. Avoid counting the same absence twice.

Recent form should describe a sustainable change beyond your baseline, rather than a single lucky result. Rest and preparation can matter on short weeks or after a bye. Travel, time-zone changes, and altitude may affect the matchup, but can overlap with home field. Matchup fit covers interactions such as pass protection against a strong pass rush; enter only the extra effect beyond overall unit quality.

Wind, rain, snow, and temperature do not automatically favor a particular team. Weather often changes total scoring more than the spread; enter a spread adjustment only for a relative advantage between these two teams. Coaching changes and preparation can matter, but subjective “motivation” is easy to overrate. In college football, verify transfers, opt-outs, suspensions, quarterback changes, and opponent quality, especially early in the season and around bowl games.

A sportsbook's line reflects its forecast plus market information, customer wagers, and risk decisions. New injury reports, lineups, weather forecasts, and other matchup news can change it. Different providers can quote different lines at the same time. This calculator does not fetch those lines; record the source and time yourself. Market activity is not added as a performance factor here, to avoid feeding the comparison line back into the estimate.

For Team A at −3, A must win by more than 3 to cover that line; exactly 3 is a push. At +3, A covers by winning or losing by fewer than 3; a 3-point loss is a push. The result checker uses the entered final scores and published spread.

The sensitivity setting adds and subtracts your chosen number from the unrounded projected margin. It explores how an assumption change can alter the favorite; it is not a measured probability range. After the game, enter both final scores to see the actual margin, prediction error, and published-line cover result. Saving adds a new snapshot, so you can preserve a pregame estimate and a separate postgame review.

Records stay in local browser storage, with a maximum of 100 snapshots. They do not sync across devices, and clearing browser data can remove them. If storage is unavailable, records last only for the current session. Export or print to keep a durable copy. CSV exports contain ratings, all adjustments, notes, dates, and scores.

The factor categories are informed by publicly described football forecasting and spread mechanics. The numerical assumptions and calculation in this tool are our own.

• ESPN: Introducing NFL Football Power Index — historical explanation of team strength, game conditions, and player availability.
• Caesars: Point spread guide — spread notation and changing market lines.

Background sources reviewed October 7, 2026. This page is independent and is not affiliated with the NFL, NCAA, ESPN, or a sportsbook.