# Wilcoxon Signed-Rank Calculator

Run a paired nonparametric Wilcoxon signed-rank test from paired samples or differences

> Canonical page: https://elysiatools.com/en/tools/wilcoxon-signed-rank-calculator

- **Category:** Math & Numbers

- **Keywords:** wilcoxon signed rank test, paired samples, nonparametric, rank test, p value, calculator

## Overview

The Wilcoxon Signed-Rank Calculator is a nonparametric statistical tool used to compare two related samples or repeated measurements on a single sample. It serves as a robust alternative to the paired t-test when data does not follow a normal distribution, analyzing the ranks of the differences between paired observations to determine statistical significance.

## Inputs

- **Input Mode** (select)
- **Before Values** (textarea): e.g. 72, 75, 78, 74, 76
- **After Values** (textarea): e.g. 76, 79, 80, 77, 81
- **Difference Values** (textarea): e.g. 4, 4, 2, 3, 5
- **Alternative Hypothesis** (select)
- **Alpha** (number)
- **Decimal Places** (number)

## When to use

- When comparing paired data that does not meet the normality assumption required for a parametric t-test.
- When analyzing ordinal data or continuous data containing significant outliers that might skew mean-based results.
- When evaluating the effectiveness of an intervention by comparing 'before' and 'after' measurements from the same subjects.

## How it works

- Calculate the difference between each pair of observations or input pre-calculated differences directly into the tool.
- Rank the absolute values of these differences from smallest to largest, excluding any pairs where the difference is zero.
- Assign the original signs (positive or negative) to the ranks and calculate the sum of the positive and negative ranks to find the W-statistic.
- Compute the p-value based on the rank sums and compare it against your chosen alpha level to decide whether to reject the null hypothesis.

## Use cases

- Medical researchers comparing patient heart rates before and after administering a specific treatment.
- UX designers evaluating task completion times for the same group of users across two different interface versions.
- Environmental scientists measuring pollutant levels at the same locations during two different seasons.

## Frequently asked questions

### What is the main difference between this and a paired t-test?

The Wilcoxon signed-rank test is nonparametric and does not require a normal distribution, whereas the paired t-test assumes the differences are normally distributed.

### Can I use this test for independent samples?

No, this test is specifically for paired or related samples. For independent samples, use the Mann-Whitney U test.

### How are zero differences handled in the calculation?

Pairs with a difference of zero are typically excluded from the ranking process, reducing the effective sample size.

### What does a p-value lower than the alpha level mean?

It indicates that the observed difference is statistically significant, providing enough evidence to reject the null hypothesis.

### Which input mode should I choose?

Use 'Paired Samples' if you have raw before/after data, or 'Differences' if you have already calculated the change for each pair.

## Related tools

- [Absolute Value Calculator](https://elysiatools.com/en/tools/absolute-value-calculator): Calculate the absolute value of positive, negative, or decimal numbers and explain the sign relationship
- [Chi-Square Test Calculator](https://elysiatools.com/en/tools/chi-square-test-calculator): Run chi-square goodness-of-fit or independence tests from observed counts or contingency tables
- [Condensing / Evaporating Temperature Calculator](https://elysiatools.com/en/tools/condensing-temperature-calculator): Estimate the saturated condensing temperature (T_cond) and evaporating temperature (T_evap) of a refrigeration circuit. Three modes: (1) from coil approach — T_cond = T_ambient + condenser ΔT approach, T_evap = T_medium − evaporator ΔT approach; (2) from measured saturated pressures — given P_cond and P_evap for a known refrigerant (R-22 / R-134a / R-410A), invert the Antoine fit; (3) from subcooling & superheat — T_cond = T_liquid − SC, T_evap = T_suction − SH. Temperature in °C/K/°F; pressure in bar/MPa/kPa/PSI absolute or gauge (atmospheric default 1.01325 bar). Results reported in °C.
- [Conditional Probability Calculator](https://elysiatools.com/en/tools/conditional-probability-calculator): Calculate P(A given B) from joint probability P(A and B) and condition probability P(B)
- [Cooling Load Calculator (Area / U-value + Infiltration)](https://elysiatools.com/en/tools/cooling-load-calculator): Estimate the cooling load of a room by the simplified ASHRAE steady-state method. Transmission sensible load Q_trans = Σ(A_i·U_i·ΔT) over envelope surfaces entered one per line as 'area,U' (U in W/(m²·K)). Infiltration/ventilation sensible Q_s = 1.23·ACH·V·ΔT and latent Q_l = 3010·ACH·V·ΔW (W), where ΔW is the indoor-outdoor humidity-ratio difference derived from dry-bulb temperature and relative humidity via the Magnus saturation fit. Total cooling load = total sensible + total latent. Temperature in °C/K/°F (only differences matter), area in m²/ft².
- [DC Motor Back-EMF & Torque Calculator (E=kω, T=kI)](https://elysiatools.com/en/tools/dc-motor-back-emf): Compute the back-EMF and electromagnetic torque of a DC motor from its machine constant: E=k·ω, T=k·I. In SI units the back-EMF constant equals the torque constant (k_e=k_t=k, V·s/rad=N·m/A). Also returns the mechanical (air-gap) power P=T·ω=E·I. Speed accepted in rad/s or RPM.
- [Dew Point Calculator HVAC (Magnus Equation)](https://elysiatools.com/en/tools/dew-point-calculator-hvac): Compute the air dew-point temperature from dry-bulb temperature and a humidity reading using the Magnus saturation-pressure equation: P_ws(T) = 0.6108·exp(17.27·T/(T+237.3)), P_w = φ·P_ws, T_dp = 237.3·ln(P_w/0.6108) / (17.27 − ln(P_w/0.6108)). Also returns the saturation vapour pressure P_ws, actual partial pressure P_w, and absolute humidity ρ_v (kg/m³). Three input modes: relative humidity φ (natural ventilated), August natural-ventilated wet-bulb T_w, or aspirated (Assmann) wet-bulb T_wa. Temperature in °C/K/°F; all reported temperatures are in the selected Temperature Unit.
- [Drag Force Calculator (F_D = ½·ρ·v²·C_D·A)](https://elysiatools.com/en/tools/drag-force-calculator): Compute the drag force on a body in a fluid stream: F_D = ½·ρ·v²·C_D·A (N), where ρ is the fluid density, v the free-stream velocity, C_D the drag coefficient (shape- and Reynolds-dependent), and A the reference (frontal projected) area. A built-in shape library supplies typical high-Re C_D values: sphere 0.47, hemisphere 0.42, long cylinder 0.81, disk/flat plate 1.17, cube 1.05, streamlined airfoil 0.04, long streamlined ellipsoid 0.07, cone 0.50; or choose 'Custom' to enter C_D directly. Optionally, with dynamic viscosity μ and characteristic length L, the Reynolds number Re = ρ·v·L/μ is computed, and the power dissipated by drag P = F_D·v (W). Density in kg/m³/g/cm³, velocity in m/s/km/h, area in m²/cm²/mm², length in m/cm/mm.

## Samples

- [Web Image Processing Python Samples](https://elysiatools.com/en/samples/web-image-processing-python): Web Python image processing examples using PIL/Pillow including reading, saving, resizing, and format conversion
- [Android Image Processing Java Samples](https://elysiatools.com/en/samples/android-image-processing-java): Android Java image processing examples including reading/saving images, scaling, and format conversion
- [Android Image Processing Kotlin Samples](https://elysiatools.com/en/samples/android-image-processing-kotlin): Android Kotlin image processing examples including reading/saving images, scaling, and format conversion
- [Web Image Processing Rust Samples](https://elysiatools.com/en/samples/web-image-processing-rust): Web Rust image processing examples including image read/save, scaling, and format conversion

## Related content

- [Audio Encoding and Format Conversion Tools](https://elysiatools.com/en/hubs/audio-convert): Compare audio format conversion, bitrate changes, sample-rate conversion, codec swaps, and export tools in one hub for delivery and archive workflows.
- [Image Format Conversion and Animated Export Tools](https://elysiatools.com/en/hubs/image-convert): Compare image format converters for JPG, PNG, GIF, AVIF, WebP, TIFF, ICO, base64, and animation-friendly exports in one hub.
- [JSON Interchange and Format Translation Tools](https://elysiatools.com/en/hubs/json-convert): Compare JSON conversion tools for CSV, YAML, TOML, GraphQL, XML, Markdown, Excel, BSON, EDN, and related structured formats in one hub.
- [Color Space Conversion Tools for Web and Print](https://elysiatools.com/en/hubs/design-convert): Curated tools for web-to-print color space conversion in one hub.
