MSE Calculator

Mean squared error (MSE) is the average of the squared differences between actual and predicted values. Because errors are squared, large mistakes are penalized heavily. Paste one "actual, predicted" pair per line and get MSE, plus RMSE, MAE, and the number of pairs.

One pair per line: actual value, then predicted value — e.g. "3, 2.5".

Result

Enter your values and press Calculate — the result appears here.

Worked examples

Small errors

  • pairs = 3, 2.5 -0.5, 0 2, 2 7, 8

Result: MSE 0.375

Perfect predictions

  • pairs = 10, 10 20, 20 30, 30

Result: MSE 0

One large outlier

  • pairs = 1, 1 2, 2 3, 10

Result: MSE 16.67 — the outlier dominates

Frequently asked questions

What does MSE measure?

The average squared difference between predictions and reality. It is always ≥ 0, and 0 means perfect prediction. Squaring means an error of 10 contributes 100 times more than an error of 1, so MSE is sensitive to outliers.

What are the units of MSE?

Squared units of the target variable. If you predict prices in dollars, MSE is in dollars squared, which is hard to read — which is why RMSE (the square root) is often reported alongside it.

MSE or MAE?

MSE heavily penalizes large errors and rewards models that avoid them; MAE treats all errors equally and is robust to outliers. If outliers matter to your use case, prefer MSE; if you want a typical-error view, prefer MAE.

💬 Discuss on BestWordz Community

Join the conversation about Machine Learning, mse, mean squared error on the BestWordz Community forum.

Visit Forum →
Copied!