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Sharpe & Sortino Ratio Calculator

Calculate Sharpe, Sortino, and Treynor ratios from portfolio returns with risk-free rate adjustment and rolling period charts.

Tested tool guide Tested browser tools Checked August 16, 2026

What Sharpe & Sortino Ratio Calculator does and how it behaves

A 15% return sounds impressive until you see the 30% drawdown that produced it. This ratio calculator separates the two questions - how much a portfolio earned and how much risk it carried - by computing Sharpe, Sortino, and Treynor ratios from a return history, subtracting the risk-free rate you enter, and charting each ratio over rolling windows. The common surprise: these numbers only mean something in comparison. A Sharpe of 1.0 says nothing by itself; it says something only next to another fund's Sharpe, computed the same way.

How the result is produced

1

The shared numerator

Both Sharpe and Sortino start from the same number: average return across the periods you enter, minus the risk-free rate you supply. Sharpe divides by the standard deviation of returns, so large swings in either direction reduce it. Sortino divides by downside deviation instead - volatility measured from the losing periods only - so profitable months never penalize it. Match the risk-free rate's period length to your returns, or every result shifts.

2

Treynor and the rolling view

Treynor is the only ratio needing a second series: it divides mean excess return by beta, estimated from how your portfolio's returns move with a benchmark you provide, so the result depends on which benchmark you pick. The rolling charts recompute the selected ratio over a trailing window that slides forward through your data, showing whether a strong full-sample number reflects consistent behavior or one favorable stretch.

Good uses

  • Choosing between two funds with different volatility: the fund with the higher raw return is not automatically better, and the risk-adjusted comparison tells you which one delivered more return per unit of risk.
  • Vetting a strategy marketed as downside-protected: Sortino ignores upside volatility by design, so it is the honest check of whether losses were truly rare and small rather than hidden inside a volatile return stream.
  • Testing a portfolio against its market exposure: Treynor's return per unit of beta shows whether the premium over cash compensates you for the market risk you carry, and lets you compare managers against the same benchmark.

Limits and checks

  • These ratios are comparisons, not verdicts. A Sharpe of 1.5 means nothing in isolation; it only matters next to another portfolio's Sharpe computed with the same risk-free rate and frequency, or against a long-run average for the same asset class. Reversing a ranking across benchmarks is possible, so keep everything you compare on identical inputs.
  • Period length and annualization conventions. A monthly series annualized with the square-root-of-12 rule will not match annual figures quoted elsewhere, and mixing monthly and quarterly observations in one series distorts the standard deviation. Confirm whether the tool reports per-period or annualized values before quoting the number.
  • Small samples and undefined ratios. With only a few periods, standard deviation estimates are noisy, and if no period falls below the target, downside deviation is zero and Sortino is undefined - the tool returns no number, which is not the same as zero risk. Rolling-window charts also jump when a big losing month exits the window; a moving chart can be a sample-size artifact rather than a change in the portfolio.

Common questions

What risk-free rate should I enter?

Use a short-term government yield that matches your return frequency: a monthly rate for monthly returns, an annual rate for annual returns. Consistency matters more than precision - as long as every comparison uses the same rate, rankings stay valid even though the absolute values shift. The rate enters the numerator of all three ratios, so they all move together when you change it.

Why is my Sortino much higher than my Sharpe?

Usually because Sortino ignores upside volatility: a portfolio with steady gains and rare losses can show a Sortino several times its Sharpe, and that gap is the point of the measure. If the value is enormous or absent, check your data - with no losing periods, downside deviation is zero and the ratio is not defined rather than impressive.

References and verification

The behavioral notes were checked against the browser implementation. Standards and primary references below define the relevant format, formula, or platform behavior.

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