What is Metaculus? How the forecasting platform works, how it scores you, and how it differs from prediction markets
Metaculus is a free forecasting platform, not a market: you submit probabilities, the site aggregates them and scores everyone. How the community prediction, peer and baseline scores, tournaments and resolution work, and how to use Metaculus alongside Polymarket and Kalshi.
In this article
Metaculus is a free online forecasting platform. Instead of buying and selling contracts, you give a probability (or, for number questions, a range) and Metaculus combines everyone's forecasts into a community prediction. When the question resolves, every forecaster is scored. There is no money at stake on ordinary questions, which lets Metaculus ask long-range questions that real-money markets struggle with, such as when AI will reach a given milestone.
Metaculus at a glance
| Metaculus | |
|---|---|
| Founded | 2015 |
| How it works | Forecasters submit probabilities; Metaculus aggregates them |
| Money | None on regular questions; cash prizes in some tournaments |
| Question types | Yes/no, numeric, date and multiple choice |
| Scoring | Baseline and peer scores, leaderboards and medals |
| Known for | AI, science, geopolitics and long-range questions |
How forecasting on Metaculus works
- Pick a question. Each one has precise resolution criteria, a source and a closing date.
- Submit a forecast: a probability for yes/no questions, a probability distribution for numbers and dates. You can update it as often as you like until the question closes.
- Read the comments. Many forecasters explain their reasoning, often with data, which is one of the best parts of the site.
- Get scored when the question resolves.
The community prediction is an aggregate of everyone's latest forecasts that gives more weight to recent updates, so it moves as new information arrives, much like a market price but without trading.
How Metaculus scores forecasts
Metaculus scores are based on the log score, which rewards putting high probability on what actually happened and punishes confident misses hard (how this compares with the Brier score: Brier score explained):
- Baseline score: how you did against chance. For yes/no questions a perfect forecast scores +100, and you can go negative.
- Peer score: how you did against everyone else who forecast the same question. The average peer score is zero by design, so a positive peer score means you beat the crowd.
Scores are averaged over the time a question is open, so forecasting early and keeping your forecast up to date both count. Leaderboards and medals rank forecasters over time.
Tournaments and prizes
Metaculus runs tournaments, some with cash prizes, on themes such as quarterly current events, specific countries or AI. It has also run forecasting contests for AI bots, comparing machine forecasters with its human community. Tournament rules, including scoring, are set on each tournament's page.
How questions resolve
Metaculus staff resolve questions using the stated criteria. If something happens that makes a question meaningless, for example its premise turns out to be false, the question can be annulled and nobody is scored. This is a big difference from markets, where money has to go somewhere (how Kalshi and Polymarket resolve markets).
Is Metaculus accurate?
Metaculus publishes its own track record, and its community prediction has been well calibrated over thousands of resolved questions. Because it aggregates many forecasters, it tends to beat most individuals, the same "wisdom of crowds" effect that makes markets work. Comparison with markets: how accurate are prediction markets.
Metaculus vs prediction markets
| Metaculus | Polymarket and Kalshi | |
|---|---|---|
| Incentive | Scores, reputation, some prizes | Money |
| Long-range questions | Strong: no capital is tied up | Weak: money locked for years earns little |
| Short-term events | Good | Excellent: prices react in minutes |
| Explanations | Comment threads with reasoning | Mostly just prices |
| Cost | Free | Fees on trades |
They work best together. When the Metaculus community and a market disagree by a wide margin, read the Metaculus comments and the market's rules: one of them often knows something the other has not priced in. Play-money markets are a third option: Manifold Markets explained.
Metaculus: frequently asked questions
Is Metaculus free?
Yes. Forecasting is free, and some tournaments pay prizes.
Is Metaculus a prediction market?
Not exactly. There is no trading; it aggregates forecasts. It is usually called a forecasting platform.
How does Metaculus scoring work?
Log-based scores: the baseline score compares you with chance, and the peer score compares you with other forecasters on the same question.
Metaculus or Manifold?
Metaculus for carefully worded questions and scored forecasting; Manifold for a market feel with play money and questions anyone can create.
