# Reaction Rate Calculator

Fit zero-order, first-order, and second-order rate equations to concentration-time data. Get reaction order, rate constant k, half-life t½, and R² goodness-of-fit.

> Canonical page: https://elysiatools.com/en/tools/reaction-rate-calculator

- **Category:** Math & Numbers

- **Keywords:** reaction rate, kinetics, rate constant, half life, first order, second order, zero order, r squared, chemistry

## Overview

Enter your experimental concentration-vs-time data points and the tool fits all three integrated rate laws in parallel: zero-order ([A] vs t), first-order (ln[A] vs t), and second-order (1/[A] vs t). It reports each model's rate constant k, the linearization R², and the half-life, then identifies which order best fits your data (highest R²). Ideal for general-chemistry kinetics labs where you need to determine the reaction order from experimental data.

## Inputs

- **Data Points (time, concentration — one per line)** (textarea): 0, 1.000 100, 0.500 200, 0.250 300, 0.125 400, 0.0625

## When to use

- Determine the likely reaction order from experimental concentration-time measurements.
- Calculate the rate constant and half-life for a zero-, first-, or second-order reaction.
- Compare linearized kinetic models using their R² values in a chemistry lab.

## How it works

- Enter one time and concentration pair per line in the format time, concentration.
- The tool fits \[A\] versus time for zero-order kinetics, ln\[A\] versus time for first-order kinetics, and 1/\[A\] versus time for second-order kinetics.
- It calculates the rate constant k, half-life, and linearization R² for each model.
- The model with the highest R² is identified as the best fit for the supplied data.

## Use cases

- Analyze concentration decay data from a general-chemistry kinetics experiment.
- Verify first-order behavior when a reactant concentration halves at regular time intervals.
- Identify second-order behavior when the reciprocal concentration changes linearly with time.

## Frequently asked questions

### What data should I enter?

Enter concentration-time pairs, with one pair per line, such as 0, 1.000.

### Which reaction orders does the calculator test?

It tests zero-order, first-order, and second-order rate laws.

### How is the best reaction order selected?

The calculator selects the model with the highest linearization R².

### What results does the tool report?

It reports reaction order, rate constant k, half-life, and R² for the fitted models.

### Can I use experimental chemistry data?

Yes. Enter your measured concentration-time points in the required one-pair-per-line format.

## Related tools

- [Kinetic Energy Calculator (KE = ½mv²)](https://elysiatools.com/en/tools/kinetic-energy-calculator): Compute kinetic energy, mass, or velocity from the other two, with momentum and km/h conversion
- [Recipe Ingredient Scaler](https://elysiatools.com/en/tools/recipe-ingredient-scaler): Rescale any recipe's ingredient list to a new serving count, converting cups/tbsp/tsp ⇄ grams/ml with per-ingredient densities and kitchen-friendly fraction output.
- [Adjusted R-Squared Calculator](https://elysiatools.com/en/tools/adjusted-r-squared-calculator): Calculate adjusted R squared from R squared, sample size, and predictor count
- [Air Changes per Hour (ACH, n = Q/V)](https://elysiatools.com/en/tools/air-changes-per-hour): Compute the air change rate (ACH / n) of a room from the outdoor supply airflow Q and the room volume V: n = Q/V (1/h). Three modes: solve ACH (given Q and V), solve airflow (given n and V), or solve volume (given n and Q). Flow in m³/s/m³/h/CFM, volume in m³/ft³/L. Also reports the well-mixed single-zone purge time to reach a target residual fraction ε (default 1%): t = −ln(ε)/n hours.
- [Bearing Life L10 Calculator](https://elysiatools.com/en/tools/bearing-life-l10): Calculate the basic rating life of a rolling bearing: L10 = (C/P)^p, with p = 3 for ball bearings and p = 10/3 for roller bearings. When a speed is provided, converts to L10h in operating hours.
- [Bolt Torque Clamp Force Calculator](https://elysiatools.com/en/tools/bolt-torque-clamp-force): Convert between bolt tightening torque and axial clamp force. T = K·F·d, where K is the nut factor (~0.20 for dry steel). Solve torque from force, or force from torque.
- [Carmichael Function λ(n) Calculator](https://elysiatools.com/en/tools/carmichael-function): Group exponent λ(n) from prime factorization with φ(n) comparison, primitive-root existence, Korselt's Carmichael-number detection, and optional sample-unit verification.
- [Permutation / Combination / Subset Generator (With Repeats)](https://elysiatools.com/en/tools/combinatorial-generation): Deduplicated, lexicographic permutations / combinations / subsets of up to 12 items with exact multiset counts; display capped at 200 entries.

## 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