Air to Fuel Ratio Calculator

Air to Fuel Ratio Calculator calculator can be used to determine the ideal air-to-fuel ratio for combustion engines based on fuel type and desired performance.

Input Parameters

Calculation Results

Calculation Formula

AFR (Actual) = AFR (Target) × (1 + Altitude Factor) × (1 + Temperature Factor)

Where:
AFR (Actual) = Actual Air-Fuel Ratio
AFR (Target) = Target Air-Fuel Ratio
Altitude Factor = 1 + (Altitude / 1000)
Temperature Factor = 1 - (Temperature / 100)

Air to Fuel Ratio Calculator Calculator Usage Guide

Learn how to use the Air to Fuel Ratio Calculator calculator and its working principles

How to Use the Calculator

  1. Select the type of fuel from the dropdown menu.
  2. Enter the target air-fuel ratio (AFR) in air-fuel ratio units (e.g., 14.7 for gasoline).
  3. Enter the altitude in feet (e.g., 0 for sea level).
  4. Enter the ambient temperature in degrees Celsius.
  5. Click the "Calculate" button to compute the actual air-fuel ratio and fuel air mass ratio.

Understanding Air-Fuel Ratio

The air-fuel ratio (AFR) is the mass ratio of air to fuel used in an internal combustion engine. It is a crucial parameter that affects engine performance, fuel efficiency, and emissions.

A perfect air-fuel ratio (AFR = 14.7 for gasoline) provides complete combustion with minimal waste. Rich mixtures (AFR < 14.7) have more fuel than air, while lean mixtures (AFR > 14.7) have more air than fuel.

Factors Affecting AFR

The actual air-fuel ratio is affected by several factors:

  • Altitude: As altitude increases, air density decreases, requiring more fuel to maintain the same AFR.
  • Temperature: Higher temperatures reduce air density, requiring more fuel for the same AFR.
  • Fuel Type: Different fuels have different energy contents, affecting the fuel air mass ratio.

Applications

This calculator is useful for:

  • Tuning engines for optimal performance
  • Adjusting carburetor or fuel injection systems
  • Understanding engine emissions