A giant with a tiny menu!
Blue whales mostly eat krill—tiny shrimp-like animals. The pink swarm shows tiny shrimp-like krill.
Meet our example whale: 25 metres long and about 100,000 kg. Real whales come in different sizes.
Dive into the numbers
That's one
HUNGRY ocean!
Pick an ocean giant. How big would its dinner be?
A blue whale's food for 1 day
6,000 kgThat's the weight of about 60,000 little fish!
A rounded feeding-day estimate—not an exact meal plan.
THE SAME-SCALE SEAAnimal + diver + food group share one size scale.
Meet a krill! · Enlarged viewA tiny, see-through swimmer with long antennae, lots of legs and big black eyes. About 5 cm long in our example.
On a phone? Swipe sideways to explore. The diver is 1.7 m tall (before fins).
How long is that?
Line them up!
Drag or tap people and cars to line them up end to end beside the animal.
You matched it!
People lie head to toe for this length comparison. Each person is 1.7 m tall; each car is 4.5 m long. The smallest whole number that reaches the animal’s length earns a 🤩! Swipe sideways on a phone.
67cars weigh about as much as this whale
1,429grown-ups weigh about as much
6%of its body weight in food over your chosen time
Try it yourself
Can you balance the beast?
Drag people or cars onto the right pan. On a phone, drag or tap a weight.
You balanced it! ✨
The whale is heavier. Add some weights!
Your pan: 0 people + 0 cars
The scale compares weight. Pictures on the pans are enlarged to see clearly. People overlap as the crowd grows; large crowds use sample pictures, and the count includes everyone. Use “Line them up!” above to compare actual sizes. Within 1% counts as balanced!
A whole dinner made visible
Imagine a whole swimming swarm of tiny krill!
Tiny krill for whales; little fish for sharks. Each shares the animal’s metre scale.
Whales eat much more on feeding days than on migration days. This is a fun “what if?” calculator.
Close-enough comparisons: one grown-up = 70 kg · one car = 1,500 kg · one little fish = 100 g · one krill = 1 g. Food volume is approximate: krill use 1 kg per cubic metre (1,000 example 1 g krill); the fish school uses 5 kg per cubic metre to leave swimming space. The animal drawings are illustrations; their nose-to-tail lengths and the diver's body height use the same metre scale.
For curious kids, parents & teachers: estimates and sources
We use rounded examples, not a feeding guide. The blue whale is an illustrative 25 m, 100,000 kg animal with a 6,000 kg feeding-day estimate. NOAA describes blue whales feeding mainly on krill and some large whales eating up to around six tons daily; published feeding estimates vary widely. The normal adult great white example is 4.5 m and 700 kg, with a rough food estimate of 10.5 kg/day. The record-size option uses the historically reported 6.4 m Cuban shark from 1945 listed by Guinness World Records, with an estimated 3,200 kg weight and a rough food estimate of 48 kg/day. Historical record measurements are debated; the weight was estimated, not weighed. This uses 1.5% of body mass as a rough educational extrapolation from shark feeding research, not a measured diet for this particular size.
For any selected period, food = daily estimate × days. “1 year” means 365 days. Especially for whales, multiplying a feeding-day rate for 365 days is a hypothetical constant-feeding scenario, not an estimate of a real calendar year's diet. Sharks also eat irregular meals, not identical portions every day. Food counts compare mass only, not nutrition or calories.
The record option uses the heaviest documented blue whale: 190 tonnes and 27.6 m long. The longest documented whale was a different individual, measured at 33.57 m. Its weight was not recorded. The length game uses the longest whale (33.57 m) when record whales are selected; the food and weight games use the heaviest whale (190 tonnes, 27.6 m). These are different animals. The record option retains the same illustrative food estimate; it is not a measured diet for that whale.
- Research: three-dimensional structure and variable density of krill schools
- Australian Antarctic Program: what krill look like
- Guinness World Records: great white shark sizes and historical record
- Guinness World Records: heaviest and longest blue whales
- NOAA Fisheries: Blue whale size and diet
- Semmens et al. (2013): Feeding requirements of white sharks
- Smithsonian Ocean: why whale feeding estimates vary
Food-display radius = cube root of [3 × (food kg ÷ density) ÷ (2 × π)], using 1 kg/m³ for krill and an illustrative 5 kg/m³ for the fish school. Both swimming groups use a simplified ellipsoid, twice as wide as it is tall; volume therefore grows in proportion to food mass. Shark food is shown as roughly 20 cm fish (100 g each); whale food is shown as roughly 5 cm krill (1 g each). These are rounded educational examples. The fish school leaves visible gaps; its loose packing density is an illustrative choice, not a measured school density. Real schools vary widely in spacing. Tiny krill markers have a minimum drawing size for visibility; the swarm dimensions, animal and diver retain their metre scale. Both displays show a sample at the front, with the remaining animals behind them. The krill example uses 1,000 individuals/m³, a plausible schooling density rather than a universal average; natural swarms can be much denser or much more diffuse. The displayed group contains only your calculated food amount, not necessarily a complete wild swarm. The diver is a size illustration, not an invitation to swim beside wild animals.