Population Growth Calculator

Model population dynamics using exponential or logistic growth equations for ecology and demographic studies.

Population Projection

Final Population
Growth Factor
Doubling Time:
Absolute Growth:

About This Calculator

Model population growth for species, demographics, or any population study. Choose exponential growth for unlimited resources, or logistic growth to account for environmental carrying capacity and competition.

🧮 Growth Models

Exponential Growth:
P(t) = P₀ × e^(rt)
Unlimited growth, J-shaped curve
Logistic Growth:
P(t) = K / (1 + ((K-P₀)/P₀) × e^(-rt))
Limited by carrying capacity, S-shaped curve

📊 Exponential vs Logistic

FeatureExponentialLogistic
Curve ShapeJ-shapedS-shaped (sigmoid)
LimitNone (infinite)Carrying capacity (K)
Real-world UseShort-term, abundant resourcesLong-term, limited resources

💡 Key Concepts

  • r (Growth Rate): Birth rate minus death rate per capita
  • K (Carrying Capacity): Maximum sustainable population
  • Doubling Time: t₂ = ln(2)/r ≈ 0.693/r
  • Rule of 70: Doubling time ≈ 70 / (r × 100)

❓ FAQ

Which model should I use?

Use exponential for short-term projections or populations with abundant resources. Use logistic for long-term projections or when resources are limited.

What's a typical growth rate?

Bacteria: r=0.3-2/hour. Insects: r=0.01-0.1/day. Mammals: r=0.001-0.05/year. Humans: r≈0.01/year globally.

? Frequently Asked Questions

How accurate is this

This calculator uses standard formulas and provides accurate results for typical use cases. For professional or critical applications, always verify results with certified professionals or official sources.

Is this calculator free to use?

Yes, this Population Growth Calculator • Biology • Calculator is completely free to use with no registration required. You can use it as many times as needed without any limitations.

Can I use this on mobile devices?

Absolutely! This calculator is fully responsive and works perfectly on smartphones, tablets, and desktop computers.

How do I interpret the results?

The results are displayed clearly with appropriate units. Refer to the "About This Calculator" section for detailed information.