Histogram
Histogram
A histogram divides a continuous numerical variable into equally sized intervals (bins) and displays the frequency or count of observations falling within each bin as vertical bars. Unlike a bar chart, there are no gaps between bars, reflecting the continuous nature of the data.
When to use it?
Use a histogram when you want to understand how a single numerical variable is distributed — for example, the distribution of customer ages, response times, or transaction amounts. It is the standard tool for exploratory data analysis.
What makes it effective?
Histograms reveal the shape of a distribution at a glance: whether it is symmetric, skewed left or right, bimodal, or uniform. They also highlight outliers and concentration zones.
When to avoid it?
Histograms are not suitable for categorical data or for comparing distributions side-by-side without overlapping or using small multiples. The choice of bin size significantly impacts interpretation — too few bins oversimplify, too many introduce noise.
Always experiment with bin sizes to find the resolution that best reveals the true shape of your data without overfitting to noise.
Similar Charts
Stacked Bars (Vertical)
A vertical bar chart that layers multiple data series within each bar, showing both the total and the composition of each category.
Comparison
Proportions
Stacked Bars (Horizontal)
A horizontal bar chart that stacks multiple data series within each bar, combining compositional detail with easy label readability.
Comparison
Proportions
