# A shrinkage ruler made for your clay. Pottery Ruler by PoodlePotter. Work out how big to make your piece before it shrinks in the kiln. [Choose your ruler](https://potteryruler.com/buy) · [See how it works](https://potteryruler.com/#how-it-works) ![A hand holding a centimetre clay shrinkage ruler across a freshly thrown pot on a pottery wheel](https://potteryruler.com/images/ruler-in-use-cm.webp) - 24 cm ruler / 9.45-inch ruler, in centimetres or inches. - Choose your shrinkage percentage: 10–18%. ## How it works ### Measure your wet clay Then follow the ruler’s arrows to see its fired size. OR ### Start with the size you want Then follow the ruler’s arrows backwards to see how big to make your wet clay. ![A shrinkage ruler between a wet pot on the wheel and its smaller fired size above](https://potteryruler.com/images/how-it-works-cm.webp) Photo annotations: Wet clay → Will shrink to → This size (levitation not included). Enlarged photo: Pinch or double-tap to zoom. ## The ruler ![12% clay shrinkage ruler in centimetres](https://potteryruler.com/images/rulers/pottery-ruler-12-percent-cm-transparent.webp) Enlarged ruler preview: Pinch or double-tap to zoom. Top scale: shrunk cm (also real cm). Bottom scale: wet clay cm. The inch ruler has equivalent scales in inches. Handy hole on the left. ### Dimensions 24 cm long × 2.5 cm wide × 0.2 cm thick. 9.45 inches long × 0.98 inches wide × 0.08 inches thick. ### Made for your clay Each ruler has its own shrinkage percentage. Choose from 10–18%, in centimetres or inches. Available [individually](https://potteryruler.com/buy?bundle=single) or [as a set](https://potteryruler.com/buy?bundle=complete). ### Made from durable PLA plastic With a little flex (if you’re into twanging rulers). ## Which shrinkage percentage do I need? Find your clay’s shrinkage rate. [Read our measuring guide](https://potteryruler.com/guides/measuring-clay-shrinkage) ### Start with your clay supplier Look for the shrinkage percentage on your clay’s product page or technical data sheet. Check that it covers wet-to-fired shrinkage at your firing temperature. ### Test your clay's shrinkage Measure a test piece while wet, then again after it comes out the kiln. ### Not sure which shrinkage percentage to choose? We also sell sets with a range of shrinkage percentages, whether you’re buying for yourself or as a gift. [Shop ruler sets](https://potteryruler.com/buy?bundle=complete) ## Something I made for potters like me. PoodlePotter. 👋 I’m Zoë, The Poodle Potter. I started making these rulers because I didn’t want to work out shrinkage percentages with clay on my hands (and sometimes in my hair...!). ![Zoë, The Poodle Potter, at her market table, with her poodle Kiwi resting beneath it](https://potteryruler.com/images/poodlepotter-market.webp) The potter (Zoë) and the poodle (Kiwi). ## Questions about the ruler? ### How do I choose my shrinkage percentage? Start with your clay supplier’s linear shrinkage figure, or measure a test piece through your own drying and firing process. Linear shrinkage means the change in length, not volume. Match the shrinkage rate to the stages you are measuring between. [Read our measuring guide](https://potteryruler.com/guides/measuring-clay-shrinkage). ### Can I choose a custom percentage? Choose a whole-number percentage from 10% to 18%. Need a custom percentage? [Contact us](https://potteryruler.com/contact). ### Will my finished piece fit exactly? The kiln gods don’t offer guarantees, and neither can our ruler. Clay, moisture, forming, drying and firing affect the result. Test critical dimensions and allow suitable clearance. A lid and pot made from the same clay and fired together often shrink together. ### Do you deliver to my country? We deliver to United Kingdom, Algeria, Angola, Argentina, Australia, Austria, Bahrain, Bangladesh, Belarus, Belgium, Brazil, Bulgaria, Cambodia, Cameroon, Canada, Chile, Colombia, Costa Rica, Côte d’Ivoire, Croatia, Cyprus, Czechia, Denmark, Dominican Republic, Ecuador, Egypt, El Salvador, Estonia, Ethiopia, Finland, France, Georgia, Germany, Ghana, Greece, Guatemala, Hong Kong, Hungary, Iceland, India, Indonesia, Ireland, Israel, Italy, Japan, Jordan, Kazakhstan, Kenya, Kuwait, Latvia, Liechtenstein, Lithuania, Luxembourg, Madagascar, Malaysia, Malta, Mauritius, Mexico, Morocco, Mozambique, Myanmar (Burma), Nepal, Netherlands, New Zealand, Nicaragua, Nigeria, Norway, Oman, Pakistan, Panama, Paraguay, Peru, Philippines, Poland, Portugal, Puerto Rico, Romania, Saudi Arabia, Senegal, Singapore, Slovakia, Slovenia, South Africa, South Korea, Spain, Sri Lanka, Sweden, Switzerland, Taiwan, Tanzania, Thailand, Tunisia, Türkiye, Uganda, United Arab Emirates, United States, Uruguay, Uzbekistan, Vietnam, Zambia and Zimbabwe. Select your country at checkout to see the delivery cost. ### When will my ruler arrive? - We ship our rulers from the UK with Royal Mail. - We dispatch orders the same or next day. - Estimated arrival is 2-3 days in the UK and 4-7 days internationally. - Customs clearance and local disruption can delay delivery. ## Less calculating. More making. [Choose your ruler](https://potteryruler.com/buy). [Guides](https://potteryruler.com/guides) · [Contact us](https://potteryruler.com/contact) · [Terms](https://potteryruler.com/terms) · [Privacy](https://potteryruler.com/privacy) [View this page on https://potteryruler.com/](https://potteryruler.com/)