Fantasy Keeper Calculator
Use this keeper calculator to estimate whether a player is worth keeping based on projected value, keeper cost, inflation, and risk.
What this keeper calculator actually does
In a keeper league, the real question is not “Is this player good?” It is “Is this player good for this price over the next few years?” This keeper calculator helps answer that by comparing a player’s projected market value to your league’s keeper cost rules.
Instead of relying on gut feel alone, the calculator estimates yearly surplus value and then applies a risk discount. You get a practical recommendation: strong keep, keep, borderline, or throw back.
How the keeper formula works
Step 1: Project yearly market value
The tool starts with your projected player value and grows it by inflation each year. That approximates rising auction prices and increasing draft scarcity in many keeper formats.
Step 2: Project keeper cost
It then applies your league’s annual keeper penalty (for example, +$5 each year) to estimate future keeper cost.
Step 3: Calculate surplus
For each year, surplus = market value − keeper cost. Summing those yearly values gives total gross surplus.
Step 4: Apply risk discount
Finally, gross surplus is discounted by your risk percentage, which gives a more realistic result when evaluating injury-prone or volatile players.
Input guide: what to enter
- Projected Player Value: A fair market value from your rankings, projections, or average auction data.
- Current Keeper Cost: What it costs to keep the player this year.
- Annual Cost Increase: Any annual penalty built into your league rules.
- Years You Can Keep: Remaining control years in your format.
- Market Inflation: Typical yearly jump in auction/draft prices (often 3% to 12%).
- Risk Discount: Your adjustment for uncertainty. Younger, stable stars may be 5% to 10%; risky assets can be 20%+.
- Replacement Value: What you expect from your fallback option if you do not keep this player.
Quick example
Suppose you can keep a player at $15, project him at $38 this year, keeper penalty is +$5/year, and you can keep him 3 years. If market inflation is 6% and your risk discount is 15%, you might still get significant positive adjusted surplus.
That usually means he is a strong keeper candidate—especially if your replacement option is only around $10 in value.
How to make better keeper decisions
1) Compare players using the same assumptions
Run all your potential keepers with identical inflation and risk settings. Consistency matters more than perfect precision.
2) Separate floor from ceiling
High-ceiling players can look amazing on paper. Use risk discount honestly so your decisions reflect real downside.
3) Respect league context
In shallow leagues, replacement-level talent is stronger. In deeper leagues, keepers gain relative value. Adjust replacement value accordingly.
4) Think in portfolio terms
You do not need every keeper to be “safe.” Balance stable production with upside bets, just like an investment portfolio.
Common mistakes with keeper analysis
- Ignoring inflation in leagues where elite prices rise each year.
- Using optimistic projections without accounting for age, role changes, or injury history.
- Treating all positive surplus as equal, even when one option has much higher risk.
- Forgetting opportunity cost: keeping one player may block a better keeper choice.
- Overvaluing last year’s stats instead of forward-looking projections.
Bottom line
A good keeper decision is a value decision. This keeper calculator gives you a structured way to evaluate cost, inflation, and risk instead of relying on hype. Use it before draft day, compare all your options, and keep the players with the strongest risk-adjusted surplus.