Your oldest has been on the chart since they could stand. Now there's a baby in the house, and the chart already holds a decade of marks running from knee height to somewhere near the top. You want both kids on one shared piece of family history, but you don't want a tangle of lines where nobody can tell whose mark is whose. A growth chart for siblings with a big age gap needs a plan before the first new mark goes on. Here's the layout we'd use, plus what to do if the older child's history lives on a door frame or the chart is running out of room.

Why a big age gap makes one chart tricky

In short: your younger child will spend the next ten years climbing through the exact heights your older child already marked.

All siblings pass through the same heights. What's different with a ten-year gap is timing. For a decade, your older child's marks went on with no second child in mind: full-width lines, one color, and labels with only the year. Your baby will now climb into that lower and middle stretch long after it felt finished, just as the older child's marks are nearing their last. Without a plan, the baby's age-4 mark and the older child's age-4 mark can end up a fraction of an inch apart, in the same color.

Two other things make it harder:

• Marks crowd in the middle. Kids grow fastest in the first couple of years, then settle into a slower, steadier pace, so preschool and grade-school marks tend to stack close together. That's exactly where both kids overlap. Our age-by-age guide to how much kids grow each year shows how tight that spacing gets.
• Year-only labels lose the story. A mark that just says "2019" tells your younger child nothing. "Age 4" tells them right away where their sibling stood at the same age.

Before you add a new mark: check the chart you already have

A shared chart only works if both kids are measured against the same true height. Spend ten minutes on these checks first.

1. Confirm the hanging height. Many canvas charts don't start at zero; they begin a few inches up so they clear the baseboard. Whatever number is printed at the bottom, that line should sit exactly that far above the floor. Measure from the floor itself, not the top of the baseboard.
2. Spot-check one old mark. Run a tape measure from the floor to one of your older child's recent marks and compare it to the printed number. If the chart has been taken down, moved or rehung, it may have shifted. Fix the hanger before anyone gets a new mark.
3. Look at the room left above. Check how much space sits above your older child's latest mark. If they're close to the top, read the section on second charts below before you commit to one chart.
4. Bring in marks from anywhere else. If some of your older child's history lives on a door frame or an old wall, copy it over now, into their lane. Our guide to transferring old pencil wall marks onto a growth chart walks through measuring and logging each one.

The staggered-lane layout, step by step

In short: each child owns one side of the chart, one color and one starting tag, and their marks never cross the middle.

1. Split the chart into two lanes. Don't draw a line; just decide. If your older child's old marks are short or sit mostly on one side, they keep whichever side their marks already favor. If most of their old marks run across the whole width and cross the middle, this chart isn't a good candidate for lanes, because the younger child's side would run straight through those lines. See the second-chart option below instead.
2. Pick one pen color per child. If the older child has always been marked in one color, keep it. For the younger child, choose a strong contrast, like navy and deep green, or black and burgundy. Skip yellow and pastels, which are hard to read from across the room. Use fabric-safe markers and test each one on the back hem first.
3. Draw ticks from the outside edge inward. The older child's ticks start at the left edge (or whichever side is theirs) and run about two inches toward the center. The younger child's ticks start at the opposite edge and run the same length. Because neither crosses the center, two marks at the same height can't touch.
4. Write each label just above its tick, inside your child's lane, so it never drifts past the center. Keep it short: initial, age, year. For example, "J · age 4 · 2019" in the older child's lane and "R · age 4 · 2029" in the younger child's. Same height band, same age, ten years apart, and nobody has to guess.
5. Add a name tag at each starting point. This is the staggered start. At the younger child's first standing mark, write their full name and the date in their color. If the older child's first mark was never labeled, add their name tag beside it now.
6. Put a color key in a bottom corner. Something like "Navy = J (born 2015) · Green = R (born 2025)." Years from now, whoever reads the chart can decode it without asking.
7. Wait for standing marks. Before the baby can stand steadily, write their lying-down length in a notebook instead of on the chart. See when to start tracking your baby's height for how families usually time that first real mark.

Fabric marker is meant to stay put, so a wrong tick is hard to undo. If one goes astray, draw a small X through it and redraw next to it rather than scrubbing the canvas.

The staggered timeline, year by year

Here's how a ten-year gap plays out on one chart. The ages are an example; shift them to fit your own kids.

The main thing the table shows: for most of the decade, the two kids are working in different zones. The overlap is in history, not in timing. That's why lanes and age labels matter more than squeezing marks apart on the day you measure.

Labels that still make sense in 20 years

• Always include age. Year alone makes the chart a list of dates. Age turns it into a comparison your kids will actually read.
• Measure both kids on the same day. Birthdays ten years apart split the family's measuring into two events. One shared date each year, like New Year's Day, the first day of school, or a holiday gathering, keeps the years lined up across both lanes. Write each child's age as of that day.
• Keep labels short in the middle band. Marks there sit close together. Initial, age and two-digit year ("R · 5 · '30") fit where a full name won't.
• Keep a backup record. Photograph the whole chart after each measuring day and jot both heights in a note on your phone. If the chart is ever damaged, the numbers survive.

One chart, shared marks, or a second chart?

Lanes on one chart work for most families. Here's when another setup is the better fit.

A simple decision rule: if you can picture a line down the middle of your current chart without it crossing more than a few of your older child's marks, use lanes. If not, hang a second chart beside the first.

If you do start a fresh chart for both kids, consider personalizing it with the family name instead of one child's name, so it belongs to everyone from day one. Our Canvas Kids Growth Chart ($44) takes a name or short text in the font you choose, is made of 100% cotton canvas, starts at the 6-inch mark, and comes with a fabric-safe pen. You'd just add a second marker in a contrasting color for the other lane.

Canvas Kids Growth Chart

$44.00

View the Canvas Kids Growth Chart

If the chart will hang in a shared playroom rather than a nursery, you can compare both colorways in our canvas growth charts collection.

Keeping it fair when one is a teen and one is a toddler

A big age gap changes how kids feel about the chart, not just how it looks.

• Give the older child a job. Let them hold the book flat on the baby's head, draw the tick, or write the baby's label. Many teens care more about that role than about their own mark.
• Frame comparisons as history, not a contest. "This is where your sister was at your age" is a story. "You're shorter than she was" is a scoreboard. Kids grow at their own pace, and our guide to sibling height differences on one growth chart covers how to read a shared chart fairly.
• Remember what the chart is for. A home chart is a keepsake, not a medical record. Your pediatrician tracks growth on clinical charts like the ones from the CDC. If a child's growth worries you, that's the person to ask.
• Plan the older child's last mark. When they seem done growing, or before they leave home, give them a final mark with their full name and the date. That top line becomes something the younger child can look up to, literally, for years.

Setup checklist for your first shared measuring day

• ☐  Chart hung on a secure hook or nail, not above or beside the crib, and not over a changing table or climbable furniture
• ☐  Bottom measurement checked against a tape measure from the floor
• ☐  One of the older child's recent marks spot-checked for accuracy
• ☐  Any door-frame or wall marks transferred into the older child's lane
• ☐  Lane split decided: older child's side, younger child's side (or a second chart hung at the same height if old marks span the full width)
• ☐  Two fabric-safe markers in contrasting colors, tested on the back hem, capped and stored out of a toddler's reach
• ☐  Color key written in a bottom corner
• ☐  Name tag and date at each child's starting point
• ☐  Label format agreed: initial, age, year
• ☐  Shoes off, heels against the wall, a flat hardcover book held level on the head for each mark
• ☐  Photo of the full chart taken and both heights logged

The whole plan comes down to three habits: separate lanes, separate colors, and age on every label. Set them up once, on one shared measuring day, and the chart can hold a decade of two very different kids without a single mark getting lost.

Frequently asked questions