Response Times Percentile Calculator

Calculate a response-time percentile, such as p95, from your recorded timings.

How to use Response Times Percentile Calculator

1. Enter Response Times Values as matching lists where weights are used; separate numbers with commas, spaces, semicolons or new lines. 2. Enter Percentile from 0 to 100. 3. Select Calculate or press Enter, then read value at selected percentile. 4. Copy result copies the answer; Reset clears the form. Do not use thousands separators inside lists.

Why use this tool?

Inspect tail response times with a documented interpolation rule, rather than treating the average as the whole performance story.

How the calculation works

Use the inclusive R-7 convention. Sort the values, calculate the zero-based position (count − 1) × percentile ÷ 100, then linearly interpolate between neighbouring observations. Enter non-negative timings in the same unit, such as milliseconds. Results use that unit. This page processes your list; it does not run a website speed test or enforce a service-level agreement. Results use up to six decimal places, or six significant digits in scientific notation for nonzero magnitudes below 0.000001. Calculations use browser floating-point arithmetic. Each list supports up to 20,000 numbers. Entry and result magnitudes must not exceed 9,007,199,254,740,991; unrepresentable variance or weighted products are rejected. General descriptive-statistics reference: https://itl.nist.gov/div898/handbook/prc/section2/prc262.htm. Weighted conventions are defined explicitly on this page.

Example

For response times 100,120,130,450 and Percentile = 95, the selected percentile is 402.

Practical tip

State the R-7 method when comparing results with another package; other percentile definitions can differ on small datasets.