Dolls House Scale Calculator & Conversion Chart

Real size to miniature size

Miniature dimension = real dimension ÷ scale denominator

Example: a 900 mm real-world cabinet at 1:12:

900 ÷ 12 = 75 mm

So the mathematically scaled miniature dimension is 75 mm.

Miniature size to real size

Real dimension = miniature dimension × scale denominator

Example: a 75 mm-high object at 1:12:

75 × 12 = 900 mm

So it represents approximately 900 mm full size.

Convert one miniature scale to another

New miniature dimension = existing miniature dimension × old denominator ÷ new denominator

Example: a 100 mm item at 1:12 converted to 1:24:

100 × 12 ÷ 24 = 50 mm

So the equivalent 1:24 dimension is 50 mm.

The future on-page calculator should offer three modes.

Mode 1 — Real size to miniature

Inputs:

• real dimension;
• unit: mm, cm, metres, inches or feet;
• target scale: preset or custom ratio.

Outputs:

• miniature size in millimetres;
• miniature size in inches;
• exact unrounded result;
• practical rounded result.

Mode 2 — Miniature to real size

Inputs:

• miniature dimension;
• unit;
• scale.

Outputs:

• represented real-world size in mm/cm/metres;
• represented size in inches/feet.

Mode 3 — Scale to scale

Inputs:

• current miniature dimension;
• current scale;
• target scale.

Outputs:

• target miniature dimension;
• percentage of the original miniature size.

Calculator design rules

The calculator should:

• default to 1:12;
• allow custom denominators such as 1:10 or 1:20;
• never imply that a mathematically scaled result guarantees product fit;
• display metric and imperial results;
• retain enough decimal precision for very small scales;
• allow the user to copy the result;
• remain usable on mobile;
• show the formula in normal HTML below the tool so the page remains useful without JavaScript.

The descriptive names are hobby conventions. The ratio itself is the precise part.

For example, 1:12 always means one unit in the model represents twelve of the same units in full size, whether you work in millimetres, inches or another unit.

In a ratio such as 1:12:

• the first number represents the miniature;
• the second represents the real object.

So:

• 1 mm in the miniature represents 12 mm in real life;
• 10 mm represents 120 mm;
• 100 mm represents 1200 mm.

A larger denominator means a smaller miniature. That is why 1:6 is larger than 1:12, 1:12 is larger than 1:24, and 1:24 is larger than 1:48.

Pretty Miniatures specialises in 1:12 scale.

At 1:12:

Real dimension ÷ 12 = miniature dimension

In imperial terms, 1 inch in a 1:12 miniature represents 1 foot in real life. This is why 1:12 is commonly called one-inch scale.

The table below converts common real-world dimensions directly into miniature millimetres.

These are mathematical conversions. A finished miniature product may differ slightly for design, material, construction or practical reasons.

Suppose a real kitchen worktop is 900 mm high.

• 1:6 → 150 mm
• 1:12 → 75 mm
• 1:16 → 56.25 mm
• 1:18 → 50 mm
• 1:24 → 37.5 mm
• 1:48 → 18.75 mm
• 1:144 → 6.25 mm

The same real object becomes progressively smaller as the denominator increases.

A real bed measuring 2000 mm long would be:

This is useful when designing furniture from real-world dimensions, but real beds themselves come in many sizes. Scaling one particular full-size bed does not create a universal miniature bed standard.

You have a 1:12 table that measures 140 mm long.

140 × 12 ÷ 24 = 70 mm

So the equivalent 1:24 table is 70 mm long.

A 1:24 chair is 35 mm wide.

35 × 24 ÷ 12 = 70 mm

The 1:12 equivalent is 70 mm wide.

For any other combination:

new size = old size × old denominator ÷ new denominator

Sometimes you need a percentage rather than a physical dimension.

Target percentage = old denominator ÷ new denominator × 100

Example: 1:12 to 1:24:

12 ÷ 24 × 100 = 50%

So a correctly sized 1:12 drawing can be printed at 50% to produce the same design at 1:24.

Important printing warning

Do not assume that a PDF or image will print at its intended physical scale automatically.

Printer drivers and PDF viewers may apply Fit to page, Shrink oversized pages, Scale to printable area, borderless enlargement or custom zoom.

For scale-critical templates, include a known calibration box or line—such as 50 mm—and measure the printed result before cutting material.

Pretty Miniatures uses both millimetres and inches in customer-facing measurements, but millimetres are particularly convenient for miniature design because small differences are easy to express and CAD/laser workflows commonly use metric dimensions.

Example:

875 mm ÷ 12 = 72.9167 mm

That can be interpreted as approximately 72.9 mm or 73 mm, depending on the application.

Do the calculation first, then decide how much precision is useful.

Furniture planning

Rounding to the nearest 1 mm may be adequate for an early room layout.

Product-fit checking

Use the actual product measurements rather than a theoretical scale calculation.

CAD or laser cutting

Keep more precision until the design is complete, then adjust deliberately for material thickness, kerf, joint fit, hardware and assembly clearance.

Very small scales

At 1:48 or 1:144, fractions of a millimetre can become significant, so premature rounding can visibly distort a design.

Suppose two real sofas are:

• Sofa A: 1800 mm wide
• Sofa B: 2200 mm wide

At 1:12:

• Sofa A = 150 mm
• Sofa B = 183.3 mm

Both can be valid 1:12 sofas, yet one is more than 30 mm wider.

A scale calculator answers “what would this real dimension become at this scale?” It does not answer “will every item labelled with this scale fit my room?”

For purchases, use the dimensions on the individual product listing and compare them with your house. See How to Measure Your Dolls House Before Buying Furniture.

A mathematically exact reduction is an excellent starting point, but miniature makers sometimes need to adapt a dimension because of:

• material thickness;
• strength;
• laser-cutting kerf;
• minimum printable wall thickness;
• hinges and hardware;
• fabric behaviour;
• visual readability;
• assembly tolerances.

For example, dividing a real chair leg by twelve might produce a miniature component that is unnecessarily fragile in the chosen material. A maker may increase its thickness slightly while keeping the overall object visually proportionate.

This should be a conscious design decision, not an arithmetic mistake.

If a drawing has one known dimension, you can derive its scale.

Example:

A plan shows a door as 40 mm high, and the real door is known to be 2000 mm high.

2000 ÷ 40 = 50

So the drawing is approximately 1:50.

To recreate that door at 1:12:

2000 ÷ 12 = 166.7 mm

Avoid deriving dimensions from perspective photographs unless perspective distortion has been controlled.

If you know both the miniature measurement and the real measurement:

Scale denominator = real dimension ÷ miniature dimension

Example:

• real door height: 1980 mm;
• miniature door height: 165 mm.

1980 ÷ 165 = 12

So that measurement is exactly 1:12.

For an unknown dolls house, use several reference dimensions rather than relying on one feature. A planned companion guide will cover How to Tell What Scale Your Dolls House Is in detail.

Multiplying when you should divide

To make a full-size measurement smaller, divide by the scale denominator.

Thinking 1:24 is larger than 1:12

It is smaller. One twenty-fourth is half of one twelfth.

Mixing units

If the real dimension is in millimetres, the divided result is also in millimetres.

Scaling area or volume as though it were a length

The simple denominator rule above applies directly to linear dimensions. Area changes by the square of the factor and volume by the cube.

Rounding too early

Keep the calculated value until the design is complete.

Treating mathematical scale as a universal furniture size

Real furniture varies, so scaled furniture varies too.

Printing a template with “Fit to page” enabled

This can destroy the intended physical scale.

For 1:12:

• Length: divide by 12
• Area: divide by 12² = 144
• Volume: divide by 12³ = 1728

Most dolls house furniture work uses length, width and height individually, so linear conversion is normally what you need.

Example: 5 ft 6 in = 66 real inches.

66 ÷ 12 = 5.5 miniature inches

Scale itself has no preferred measurement system.

1:12 means exactly the same thing whether you say:

• 1 mm represents 12 mm;
• 1 cm represents 12 cm;
• 1 inch represents 12 inches;
• 1 inch represents 1 foot.

The one-inch-to-one-foot wording is simply a convenient imperial shorthand for 1:12.

1:6

Used for much larger fashion-doll and sixth-scale displays. See Does 1:12 Scale Furniture Fit Barbie? 1:12 vs 1:6 Explained.

1:12

The principal scale used by Pretty Miniatures and an established collector dolls house standard.

1:16 and 1:18

Seen in some vintage, toy and manufacturer-specific systems. Verify actual dimensions rather than assuming exact compatibility.

1:24

Half the linear size of 1:12 and commonly called half-inch scale.

1:48

Half the linear size of 1:24 and commonly called quarter-inch scale.

1:144

A very small micro scale. It is mathematically one twelfth of 1:12, which is why it can be used for a “dolls house within a dolls house”.

When adapting your own CAD drawing or template:

1. confirm the original scale;
2. keep an untouched master copy;
3. calculate the multiplier;
4. scale geometry uniformly in X and Y;
5. scale Z as well for 3D geometry;
6. check material thickness separately;
7. check slots, tabs and holes;
8. check minimum feature sizes;
9. make a test piece;
10. verify the physical measurement.

Important manufacturing note

Do not blindly scale material thickness and joint clearances.

A 3 mm sheet at 1:12 would mathematically become 1.5 mm if the entire design were halved to 1:24, but the correct practical solution may be to choose another available material and redesign the joint.

Likewise, laser kerf, screws, magnets, LEDs and printable wall thicknesses do not automatically scale in the same way as the overall object.

Example:

Real size: 1000 mm Scale: 1:12

Exact result:

83.333333... mm

Practical display result:

83.33 mm

A workshop may later choose 83.3 mm, 83.5 mm or another deliberate dimension. The calculator should never silently replace the mathematical result with a convenient manufacturing number.

A future printable reference sheet should include:

• the three core formulas;
• common scale names;
• one-foot equivalents;
• 1:12 metric chart;
• scale-to-scale multiplier table;
• print calibration box;
• blank calculation area.

A5 or A4 would both work well as a workshop reference sheet.

Before trusting a result, check:

• ☐ Am I converting a real dimension or a miniature dimension?
• ☐ Are all values in the same unit?
• ☐ Is the target scale written correctly?
• ☐ Did I divide real size by the denominator?
• ☐ If converting scale-to-scale, did I use old denominator ÷ new denominator?
• ☐ Have I avoided rounding too early?
• ☐ If printing, is automatic page scaling disabled?
• ☐ If manufacturing, have I considered material thickness and kerf separately?
• ☐ If buying furniture, have I checked actual product dimensions rather than relying only on scale?

Real to miniature

Miniature = Real ÷ Scale

Miniature to real

Real = Miniature × Scale

Scale to scale

New miniature = Old miniature × Old scale ÷ New scale

Those three equations cover most dolls house scale calculations.

For Pretty Miniatures products, remember that scale establishes the overall proportional system, while the listed physical dimensions remain the deciding factor for fit.

Related guides

• What Is 1:12 Scale? Dolls House Scale Guide
• How to Measure Your Dolls House Before Buying Furniture
• Does 1:12 Scale Furniture Fit Barbie? 1:12 vs 1:6 Explained
• How to Choose 1:12 Dolls House Furniture for Every Room

Planned companion guides

• How to Tell What Scale Your Dolls House Is
• 1:12 vs 1:24 vs 1:6 vs 1:16 Dolls House Scales Explained