Clear, real-world examples of 3 practical examples of line graphs

Three core, real examples of 3 practical examples of line graphs

Instead of starting with theory, let’s go straight into three concrete, practical examples of line graphs that mirror how people actually use them at work and in school. These are the backbone cases you see in dashboards, reports, and presentations.

1. Monthly sales revenue over several years

One of the best examples of 3 practical examples of line graphs is the classic monthly revenue chart. Picture a dataset with columns for Month, Year, and Revenue. When you plot revenue on the y-axis and time on the x-axis, you instantly see:

• Whether revenue is trending up or down overall
• Seasonal spikes (holiday shopping, summer slowdowns, back-to-school bumps)
• The impact of big events (product launches, ad campaigns, supply chain issues)

A practical example: An e‑commerce company tracks monthly revenue from January 2020 through December 2024. On a single line graph, you see a sharp dip in Q2 2020, a rebound in late 2020 as online shopping surged, and then steadier growth from 2021 to 2024. By 2024, the line shows smaller but more stable increases, reflecting a maturing business.

This single example of a line graph lets leadership compare pre‑pandemic and post‑pandemic performance at a glance. You can also overlay a second line for marketing spend to see whether higher ad budgets actually move the revenue line.

2. Daily COVID‑19 case counts and hospitalizations

Health data is one of the strongest real examples of 3 practical examples of line graphs, because trends and turning points matter a lot. Public health agencies like the U.S. Centers for Disease Control and Prevention (CDC) publish time-series data for cases, hospitalizations, and deaths.

If you plot daily new COVID‑19 cases from 2020 through 2025 as a line graph, you see:

• Massive waves (e.g., winter 2020–2021, Omicron in late 2021–early 2022)
• The clear downward trend in severe outcomes as vaccination and prior infection increased
• Smaller, seasonal upticks in late 2023 and 2024

Add a second line for daily hospital admissions, and you’ll notice that by 2023 and 2024, the hospitalization line is much lower relative to cases than it was in 2020. That visual tells a public-health story about immunity and better treatment. This kind of line graph is used every day by agencies like the CDC and NIH to communicate risk and policy decisions.

As an example of how these graphs are used in 2024–2025, many dashboards now show a 7‑day rolling average line instead of raw daily counts to smooth out weekend reporting noise. That’s still a line graph, just with a calculated, smoothed line.

3. Average global temperature anomalies over decades

Climate data gives another powerful example of 3 practical examples of line graphs. Instead of plotting raw temperatures, climate scientists often plot temperature anomalies: how much hotter or colder a year was compared to a long-term baseline.

Imagine a line graph with years on the x-axis (1880–2024) and temperature anomaly (°C) on the y-axis. You see a mostly flat line from 1880 through about 1970 with some wiggles, followed by a steep upward climb from the 1980s onward. Recent years like 2016, 2020, and 2023 stand near the top of the graph as some of the warmest on record. NASA and NOAA maintain this kind of data and display it in line-based charts on their sites.

This is one of the best examples of line graphs for showing long-term trends. You don’t need to be a scientist to read it: the line is going up, and it’s going up faster in recent decades. For a 2024–2025 audience, this line graph is a staple in climate reports, policy briefs, and news articles.

Expanding beyond 3: more practical line graph examples you actually see

Once you understand those three core cases, it’s easy to see more real examples of 3 practical examples of line graphs in everyday analytics. Here are several more that build on the same idea: values changing over time.

Stock prices and investment performance

Finance is packed with examples of line graphs. A simple one is the closing price of a stock—say, Apple (AAPL)—plotted daily over five years. The line shows:

• Long-term growth vs. short-term volatility
• Market crashes (e.g., March 2020) and recoveries
• Reaction to product announcements and earnings calls

A more investor-focused example of a line graph compares two or three funds on the same chart. If you plot the value of $10,000 invested in an S&P 500 index fund, a tech-heavy ETF, and a bond fund from 2015 to 2024, three lines show how different risk levels play out. This is a standard visualization in retirement calculators and brokerage dashboards.

Heart rate during a workout

Wearables like Apple Watch, Fitbit, and Garmin give another set of real examples of 3 practical examples of line graphs. During a 45‑minute run, your watch records heart rate every few seconds. Plotting time on the x-axis and heart rate (beats per minute) on the y-axis produces a line graph showing:

• Warm-up phase (gradual rise)
• Steady-state effort (plateau)
• Short sprints or hill intervals (sharp peaks)
• Cool-down (decline)

This example of a line graph is not just pretty; it’s actionable. Coaches look at the shape of that line to see if you’re pacing correctly or overtraining. Health sites like Mayo Clinic and WebMD often use similar line-style visuals to explain target heart rate zones and exercise intensity.

Blood glucose levels across a day

For people with diabetes, continuous glucose monitors (CGMs) produce one of the most personally meaningful examples of line graphs. These devices log glucose readings every few minutes. When plotted as a line over 24 hours, you see:

• Spikes after meals
• Drops during sleep or after intense exercise
• Effects of medication timing

In 2024 and 2025, more apps are layering in predictive lines—projected glucose based on recent trends—so the graph doesn’t just show history, it hints at the near future. Again, it’s the same basic structure: time along the x-axis, a clinical measure on the y-axis, and a line that tells a story.

Website traffic and user behavior

Digital analytics tools like Google Analytics and similar platforms rely heavily on line graphs. A marketing team might track:

• Daily sessions over the last 90 days
• Conversion rate by week for the past year
• Average session duration over time

Take a product launch campaign in 2024. The line graph of daily website visits shows a steep spike on launch day, a slower decline over the next week, and then a new baseline that’s higher than before. That visual is one of the best examples of how line graphs connect marketing activity to real outcomes.

If you overlay a second line for daily sign-ups or purchases, you can judge whether the traffic is high quality. Two lines moving together is a good sign; a traffic spike without a conversion spike is a red flag.

Student test scores across grades

Education research and school districts use line graphs to track student performance over time. Imagine a student’s standardized math scores plotted from 3rd grade through 8th grade. The line might show:

• Steady improvement year after year
• A dip during the pandemic years (e.g., 2020–2021)
• Recovery after targeted tutoring in 2023–2024

Researchers at universities and organizations like Harvard Graduate School of Education use similar line graphs to study learning loss and recovery. This is another example of a line graph where the slope—how fast scores change—matters as much as the absolute value.

Energy usage in a smart home

Smart meters and home energy dashboards provide modern, very practical examples of 3 practical examples of line graphs. A utility company might show hourly electricity usage for a household over 24 hours as a line graph. You can quickly spot:

• Morning and evening peaks
• A midday spike when the air conditioning kicks in
• Lower usage at night

Overlaid with outdoor temperature as a second line, the graph helps homeowners understand how weather drives their bills. In 2024–2025, many utilities and smart home platforms use this kind of line graph to nudge customers toward off-peak usage.

How to choose the right example of a line graph for your data story

With all these examples of 3 practical examples of line graphs floating around, how do you pick the one that fits your message?

Think about three questions:

1. What is the time scale?
Line graphs work at many scales: seconds (heart rate), hours (energy use), days (COVID‑19 cases), months (sales), years or decades (climate). Your time scale shapes how dense the line looks and whether you need smoothing or rolling averages.

2. Do you need one line or several?
Some of the best examples of line graphs use multiple lines for comparison: revenue vs. marketing spend, cases vs. hospitalizations, temperature vs. energy use. Just be careful not to overload the chart; two to four lines is usually the upper limit for clarity.

3. Which trend matters most: level, slope, or volatility?

• In climate and long-term sales, the overall upward or downward trend is the star.
• In stock prices, short-term volatility is part of the story.
• In health data like glucose or heart rate, both spikes and averages matter.

Pick the example of a line graph that makes your key point obvious within a second or two of looking.

Practical tips for building better line graphs in 2024–2025

To make your own examples of 3 practical examples of line graphs as clear as the ones above, a few design choices go a long way:

Label lines directly when possible.
Instead of a crowded legend, place short labels near the lines: “Revenue,” “Marketing Spend,” “Cases,” “Hospitalizations.” This is especially useful when you show multiple real examples on one chart.

Use consistent time intervals.
Mixing weekly and monthly data on the same line graph gets confusing fast. Resample your data so the x-axis ticks are evenly spaced in time.

Highlight key events.
On your sales or traffic line graph, annotate product launches, policy changes, or outages. On a COVID‑19 line graph, mark vaccination rollouts or variant waves. A few well-placed notes can turn a basic example of a line graph into a compelling narrative.

Avoid unnecessary clutter.
You don’t need heavy gridlines, 3D effects, or rainbow colors. Thin lines, readable fonts, and a clear title usually win. The best examples let the data shape speak for itself.

FAQ: common questions about examples of line graphs

Q1. What are some everyday examples of line graphs people actually use?
Everyday examples include monthly sales revenue, daily website traffic, stock prices, heart rate during workouts, blood glucose across a day, household energy usage, and student test scores over several years. All of these match the core pattern in our three practical examples of line graphs: a value changing over time.

Q2. What is an example of when a line graph is better than a bar chart?
Use a line graph when you care about the shape of change across time—trends, peaks, and turning points. For instance, a line graph of average global temperature anomalies from 1880 to 2024 makes the acceleration of warming obvious. A bar chart of the same data would be harder to read as a continuous trend.

Q3. Can I use line graphs for non-time data?
You can, but it’s trickier. Line graphs work best when the x-axis has a natural order, like time or age. Some analysts use line graphs for ordered categories (for example, age groups 0–17, 18–34, 35–49, 50–64, 65+), but if the order isn’t meaningful, lines can mislead. In most cases, the strongest examples of line graphs stick to time on the x-axis.

Q4. What makes the best examples of 3 practical examples of line graphs for teaching students?
Pick topics students care about: their own test scores over grades, local weather across seasons, or favorite sports team performance by game. These examples of 3 practical examples of line graphs are relatable, and the patterns—slumps, hot streaks, seasonal swings—are easy to discuss.

Q5. Where can I find real data to build my own examples of line graphs?
Plenty of public sources offer time-series data:

• Health and disease trends: CDC
• Medical and clinical research: NIH
• Education and learning outcomes: Harvard University and other university research sites

Download a CSV, pick a metric that changes over time, and you’re ready to build your own real examples of 3 practical examples of line graphs for reports, classes, or dashboards.