Zombie Invasion Calculator
Calculate how quickly a zombie apocalypse would spread. Model exponential growth of zombie population and estimate survival rates.
New zombies per zombie per day
Zombie Population
1,000,000
100.0% of population infected
Survivors
0
0.0% survival rate
How to Use This Calculator
- Enter the initial number of zombies.
- Enter the daily infection rate (humans infected per zombie per day).
- Enter the number of days to model.
- Enter the total human population.
- The calculator displays zombie population, survivors, and infection/survival percentages.
Zombie Infection Formula
Zombie population grows exponentially, limited by total population:
Total Zombies = Previous Zombies + New Zombies
Survivors = Population - Total Zombies
Infection % = (Zombies / Population) × 100
Survival % = (Survivors / Population) × 100
Example: 1 initial zombie, 2 infections/day, 1M population, 30 days: Day 1 = 3 zombies, Day 2 = 9, Day 10 = 59,049, Day 20 = 3.5B (exceeds population, so all infected). Exponential growth is extremely rapid and quickly overwhelms populations.
Full Description
The Zombie Invasion Calculator models how quickly a zombie apocalypse would spread if zombies could infect humans. This is a fun, fictional calculator that demonstrates exponential growth and population dynamics. In zombie fiction, each zombie can infect multiple humans per day, leading to explosive population growth that quickly overwhelms humanity.
The calculator models exponential growth: each day, each zombie infects a certain number of humans (the infection rate), creating new zombies. This leads to explosive growth—even starting with just 1 zombie and a moderate infection rate, the population can reach millions or billions in just weeks. The calculator accounts for population limits (can\'t exceed total population) and shows both zombie count and survivor count over time.
This calculator helps you model fictional zombie scenarios. Enter initial zombies, infection rate, days, and population, and it calculates zombie growth, survivors, and percentages. Use it for fun, writing, games, or understanding exponential growth. Remember, this is purely fictional—real-world factors (resistance, countermeasures, zombie weaknesses) would dramatically slow or prevent such scenarios!
Frequently Asked Questions
How does zombie infection spread?
Zombie infection spreads exponentially: Each zombie infects multiple humans per day. Population = Initial × (1 + Rate)^Days, limited by total population. Example: 1 zombie, 2 infections/day, 1M population: Day 1 = 3 zombies, Day 2 = 9, Day 10 = 59,049, Day 20 = 3.5 billion (exceeds population).
What is a realistic infection rate?
In zombie fiction, rates vary. Slow (0.5-1/day): Manageable spread, time to respond. Moderate (2/day): Standard zombie apocalypse. Fast (5-10/day): Rapid collapse. Very fast (20+/day): Instant apocalypse. The calculator lets you model different scenarios.
How long until everyone is infected?
Depends on infection rate and population. With 1 zombie, 2 infections/day, 7.8B people: ~30 days to infect everyone (exponential growth). With 5/day: ~15 days. Higher rates = faster apocalypse. Real-world factors (resistance, fighting back) would slow this.
Is this realistic?
No, this is a fun, fictional calculator! Real-world factors would dramatically affect zombie spread: human resistance, fighting back, hiding, zombie weaknesses (headshots, fire), military response, and countermeasures. The calculator models pure exponential growth for entertainment.