Measuring Length Worksheets

Measuring length means finding how long something is with a ruler, and saying the answer with a unit. The six PDFs on this page have true-size rulers in inches, half inches and centimeters, and children measure six pencils on each sheet, with answer keys. They follow standard 2.MD.A.1 and 3.MD.B.4 of the Common Core standards for grade 2 measurement and data, and the notes below explain how a ruler works and how to read it.

How to measure with a ruler

1. Line up one end of the object with the 0 mark, not the edge of the ruler.
2. Look at where the other end reaches.
3. Read the number, and say the unit: 5 inches, not just 5.

On the half-inch worksheets, the longer marks between numbers are halves. A pencil that ends on the half mark after 4 is 4 ½ inches long. Grade 3 children measure to the nearest half and quarter inch (3.MD.B.4).

Measuring length worksheets: what is in the set

There are 6 measuring length worksheets on this page, and every one has an answer key except for any cut-out games. Two sheets measure to the nearest inch, two to the nearest half inch, and two in centimeters, each with a second set for more practice.

Measuring length worksheets: the marks on a ruler

The measuring length worksheets use rulers that are printed at actual size, so they can be checked with a real ruler. Wikipedia’s article on rulers explains how the marks are made. On an inch ruler, the marks have different lengths: the longest are whole inches, and each shorter size shows half an inch, a quarter, an eighth or a sixteenth. This table shows how many marks a 12-inch ruler has for each way of dividing an inch:

The worksheets on this page use whole inches and half inches, and the centimeter rulers have a mark for every millimeter. The fractions worksheets pages explain halves, quarters and eighths, and the fractions on a number line page shows that a ruler is a number line.

Ruler worksheets: how to read a ruler

The ruler worksheets teach three steps. First, put the 0 mark at one end of the object. Second, find the other end. Third, read the number, and say the unit. When the other end is between two numbers, the length is a whole number plus a part, and the part is read from the shorter marks. This table shows what to use for different measuring jobs:

Most mistakes come from the first step. The diagram above shows a pencil that starts at the edge of the ruler, and not at the 0 mark. It reads 4 ¾, but its real length is 5 inches. Putting the pencil on the 0 mark is the most important habit in this pack.

Measuring inches worksheets: whole inches and half inches

The measuring inches worksheets ask for the nearest inch on the first sheets, and for the nearest half inch on the next ones. The nearest inch is the whole number the end of the pencil is closest to, and the nearest half inch is the closest of the marks that are a half apart. This table shows eight lengths, in eighths of an inch, and how each is measured to the nearest inch and the nearest half inch:

A length of 4 5/8 inches is closer to 4 1/2 than to 5, but to the nearest whole inch it is 5. Because the answer depends on which unit is chosen, it is a good idea to say “to the nearest inch” or “to the nearest half inch” each time.

Measure to the nearest half inch: the rule

To measure to the nearest half inch, look at where the end of the object is between two whole numbers. If it is closer to a whole number than to the half, use the whole number. If it is closer to the half, use the half. When it is exactly in the middle, round up. This table shows where the end lies for each sixteenth of an inch:

Because a half inch has 8 sixteenths, the boundaries are at 4/16 and 12/16. The worksheets on this page use pencils that end on whole and half inches, so the question is easy to answer, and the next step in grade 3 is to measure to the nearest quarter inch.

Measuring centimeters worksheets: centimeters and millimeters

The measuring centimeters worksheets use a ruler with a long mark at each centimeter and a short mark at each millimeter. Each centimeter has 10 millimeters. A length of 8 cm 4 mm is written 8.4 cm as a decimal, and 84 mm in millimeters. This table shows six lengths in three forms:

Centimeters are easier to use than inches for children who know the place value of tens, since the marks follow the same pattern as the base-ten system. The decimals worksheets pages continue this idea. An inch is 2.54 cm, so the two rulers can be compared, as this table shows for 1 to 12 inches:

Estimating length: body and object benchmarks

Before children measure, they should estimate, because an estimate helps them to catch mistakes, such as a pencil that is 70 cm long. A benchmark is something whose length is known. This table gives six everyday benchmarks in inches and centimeters:

Children can make their own benchmarks: the width of a finger, the span of a hand or the length of a footstep. They measure each with a ruler and write the length in a table. Next time they need an estimate, they use the table.

Common mistakes with measuring length

The most common mistake is not to start at 0. This table shows five mistakes, what went wrong and the fix:

Measuring length word problems

Measuring length is used to compare, to add and to find differences. Ask children to measure first, write the unit, and then answer the question:

Games and activities for measuring length

Children learn measuring length best when they play with it. These games use things that are found at home or in a classroom:

• Measure the room: measure ten objects in the room in inches or centimeters, and put them in order
• Estimate then measure: estimate the length of an object, measure it, and see who is closest
• Pencil gallery: sort pencils by length with a ruler, from the shortest to the longest
• Ruler hunt: find a ruler, a yardstick, a meter stick and a tape measure, and say what each is used for
• Make a ruler: make a paper ruler with a mark at each centimeter and use it
• Measuring bingo: a bingo card with lengths, and calling cards with pictures of objects on a ruler

Extra support and extra challenge with measuring length

For children who need more support: start with an inch ruler that has only whole inch marks, and use a real ruler beside the worksheet. Always line up the 0 mark with one end, and say the unit aloud. Do the sheet with whole inches first, then the half inches, and keep a pencil on the 0 mark while reading the other end.

For children who need more challenge: ask for the nearest quarter inch, for the difference between two pencils, for a pencil that is 8 cm 6 mm long in millimeters, and for an estimate of the length of a room in feet. Try measuring the same object in inches and in centimeters and finding how many centimeters are in an inch.

How to tell that a child is ready to move on from measuring length

Before moving on from measuring length, check that the child can do all four of these things:

1. The child starts at the 0 mark and not at the edge.
2. The child reads a length to the nearest inch and to the nearest half inch.
3. The child measures in centimeters, and knows that a centimeter has 10 millimeters.
4. The child says the unit with every answer.

When all four are true, move on to the converting units page, or the area and perimeter page.

A 20-minute lesson on measuring length

A short lesson is the best way to introduce measuring length. This 20-minute plan can be used in a classroom, at a tutoring session or at home, and it uses the worksheets at the end:

Where measuring length fits across the grades

No skill stands alone. This table shows what children learn before and after measuring length, with the standard that goes with each step:

This page is the first page of the measurement sequence. The whole sequence is on the measurement worksheets page.

Helping at home with measuring length

Parents do not need to be experts to help with measuring length. These suggestions work well, and each takes only a few minutes:

• Measure the child’s height each month on a door frame.
• Ask “how long do you think it is?” before measuring anything.
• Use a tape measure to find the length of a table or a room.
• Check that the child starts at the 0 mark.
• Find a ruler in the kitchen, and compare its inch and centimeter marks.

How to check progress in measuring length

A teacher or parent can check progress in measuring length with the answer key and a few questions. This table shows three common situations, what they mean and what to do next:

A five-day plan for measuring length

Most children need about a week of short sessions for measuring length. This plan follows the order of the worksheets on this page:

When the plan for measuring length is complete, move on to the converting units page. The whole sequence is on the measurement worksheets page.