Sharpe Ratio Calculator

How to use the Sharpe Ratio Calculator

Pick a mode

Direct input: enter portfolio return, risk-free rate, and std dev directly. From series: paste a return series (monthly or annual) and the tool computes the mean + std dev for you.

Set the risk-free rate

The risk-free rate represents what you'd earn on a "safe" alternative — usually the US 10-year Treasury yield (currently ~4.5%) or 3-month T-bill rate (currently ~5%). For non-USD portfolios use the equivalent local sovereign yield: Singapore 10Y, UK gilt, German Bund, etc.

Get the Sharpe ratio

Formula: (Return − Risk-free) ÷ Std dev. A higher number means more return per unit of risk taken. Negative Sharpe means you underperformed the risk-free alternative — cash would have been better.

Compare against benchmarks

The benchmark table shows where canonical asset classes land: T-bills ≈ 0, S&P 500 long-term ≈ 0.3-0.5, top-decile hedge funds ≈ 1-2, Renaissance Medallion (legendary) ≈ 3.4. Sustained Sharpes above 2 are extraordinarily rare.

Sharpe Ratio — the most-used (and most-abused) risk metric in finance

William Sharpe published "Mutual Fund Performance" in 1966 with one elegant insight: returns are meaningless without context for risk. A 20% return earned with extreme volatility is not the same as a 20% return earned smoothly. He proposed a simple measure — excess return per unit of standard deviation — that lets you compare any two investments on a like-for-like basis. The metric carries his name, won him a Nobel Prize in Economics (1990), and is now the single most-cited risk-adjusted-return measure in finance. Every hedge fund prospectus, every mutual fund factsheet, every robo-advisor portfolio analysis shows a Sharpe number.

The math

Sharpe Ratio = (R_p − R_f) / σ_p. R_p is the portfolio's return over a period. R_f is the risk-free rate over the same period — usually short-term government debt (T-bills). σ_p is the standard deviation of the portfolio's returns, measuring volatility. The numerator captures "did I beat cash?" The denominator captures "how bumpy was the ride?" Divide and you have "return per unit of risk." Higher = better risk-adjusted returns. Negative = you took risk for less than what cash would have paid you (terrible — you'd have been better off in T-bills).

Renaissance Technologies' Medallion Fund has produced a Sharpe ratio of ~3.4 over 30+ years — possibly the highest sustained risk-adjusted return in financial history. Most hedge funds run 0.5-1.0. The S&P 500 long-term runs ~0.5.

Where Sharpe ratio leads astray

Sharpe assumes symmetric risk (treats upside volatility the same as downside). That's mathematically tidy but real investors only fear downside. A strategy that pays off small most of the time but occasionally explodes ("picking up nickels in front of a steamroller" — LTCM, AIG sub-prime, many crypto algorithms) shows a beautiful Sharpe right up until the crash. Other limitations: (1) requires normally-distributed returns — fails for fat-tailed strategies; (2) sensitive to sample period — Sharpe varies enormously across 1-, 5-, 10-year windows; (3) doesn't capture liquidity risk — illiquid investments look better than they should. Better metrics: Sortino ratio (downside std dev only), Calmar ratio (return ÷ max drawdown), tail-risk measures (VaR, CVaR).

The APAC portfolio use case

Sharpe ratio is fundamental in Singapore's sovereign wealth investing (GIC, Temasek both publish risk-adjusted returns), every Hong Kong hedge fund's marketing deck, and Malaysia's EPF + KWAP portfolio reports. ASEAN equity markets historically run higher returns AND higher volatility than developed markets — Sharpes typically land in similar 0.3-0.7 range as US/EU. The exception: low-correlation strategies (ASEAN small-cap, certain commodity exposures) can post higher Sharpes when sized and timed correctly. Use Sharpe as one of multiple metrics — never alone.

10 Things to Know About Sharpe Ratio

01

William Sharpe published the original metric in 1966 in "Mutual Fund Performance." He won the Nobel Prize in Economics in 1990 (shared with Markowitz + Miller for portfolio theory).

02

The S&P 500's long-term Sharpe is ~0.4-0.6 (10% return, 4.5% risk-free, 16% std dev). Most equity strategies hover here despite marketing claims.

03

The Renaissance Medallion Fund reportedly has a Sharpe ratio of ~3.4 over 30+ years — possibly the highest sustained risk-adjusted return in financial history. Closed to outside investors since 1993.

04

"Annualised" Sharpe = monthly Sharpe × √12 (assuming returns are independent). Sharpes are usually quoted annually for comparability.

05

The Sortino ratio (Frank Sortino, 1994) is a variant that only uses downside volatility in the denominator — argues that upside variance shouldn't count as "risk."

06

Bitcoin's 10-year Sharpe ratio (2014-2024) is roughly 0.6-0.8 — high return (~60% annualised) but extreme volatility (~80%) make the risk-adjusted picture more modest.

07

The Sharpe ratio paradox: a strategy that frequently delivers small gains and occasionally blows up (e.g., selling out-of-the-money options) can look great on Sharpe until the crash arrives. LTCM had a Sharpe of ~4 the year before it imploded.

08

Sharpe assumes normally-distributed returns. Real financial returns have fat tails (more extreme outliers). For tail-heavy strategies, use Sortino, Calmar, or Omega ratios.

09

To "game" Sharpe: pick periods of low realised volatility, use a stale risk-free rate, or smooth returns through illiquid asset marks. Many hedge fund Sharpes presented to LPs are inflated this way.

10

Sharpe ratio is scale-invariant: doubling all returns and volatilities leaves it unchanged. This is why it's used to compare funds of different sizes and leverages on equal footing.

Frequently Asked Questions

Rough guide: below 0 = bad (worse than cash). 0-0.5 = sub-par. 0.5-1.0 = acceptable, typical of broad equity indices. 1-2 = good, top-quartile hedge funds. 2-3 = excellent, rare. Above 3 = exceptional or suspicious — verify methodology.
Match the duration of your investment. Short-term portfolio analysis → 3-month T-bill. Long-term retirement portfolio → 10-year Treasury. For non-USD investments, use the equivalent local sovereign yield (Singapore SGS 10Y, German Bund, UK gilt).
Sample (n-1 divisor, Bessel correction) for actual return series — that's what this tool uses. Population (n divisor) only if you somehow have the entire infinite population of returns, which you don't in finance.
Multiply by √12 (square root of periods per year). Daily Sharpe × √252 (trading days). The √ assumes returns are independent across periods, which is approximately true for liquid markets. For autocorrelated returns the adjustment is more complex (use Newey-West).
Because the portfolio's return is below the risk-free rate. You took risk and earned less than cash would have paid. Common during bear markets (2008, 2022) or for poorly-allocated portfolios. Negative Sharpe → cash would have been objectively better.
By construction, the risk-free rate has zero volatility (that's why it's "risk-free"). The denominator only needs the portfolio's σ. For more rigour use the std dev of "excess return" (portfolio return − risk-free), but the difference is small in practice.
When the upside volatility doesn't bother you. Sortino only uses DOWNSIDE std dev — penalises losing volatility, ignores winning volatility. Useful for asymmetric-return strategies (long options, venture investing, anything with positive skew).
For statistical significance: at least 36 monthly returns (3 years). For confident judgement: 5+ years. Sharpes computed on 12 months or less are highly noisy — they reflect the specific period more than the strategy.
Sharpe still works mathematically. Bitcoin's high returns combined with high volatility produce Sharpes that aren't catastrophic (~0.6-0.8 long-term). But Sharpe alone doesn't capture the "I could lose 80% in a year" reality — supplement with max drawdown analysis (Calmar ratio).
No. All calculation happens entirely in your browser via JavaScript. Open DevTools → Network and watch — there's zero outbound traffic. Safe for confidential portfolio analysis.

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