# Kilnshrink — Pottery shrinkage calculator

> Pottery shrinkage calculator (iPhone/iPad app by Robert Corbin.)

- Source: https://appshunter.io/ios/app/kilnshrink/id6777078165 (this page in markdown: same URL + `.md`)
- Developer: [Robert Corbin](https://appshunter.io/developer/1890247992)
- Category: Utilities, Education
- Price: $3.99
- Age rating: 4+
- Requires: iOS 17.0 · 31 MB
- Languages: American English
- Released: 2026-06-11
- Data updated: 2026-08-14
- User reviews in markdown: https://appshunter.io/ios/app/kilnshrink/id6777078165/reviews.md

## What is Kilnshrink?

Kilnshrink is a pottery shrinkage and studio planning utility for ceramicists, pottery students, and teachers. Clay changes size during drying and firing; Kilnshrink helps you plan the wet dimensions, fired dimensions, capacity, clay weight, and batch notes before the work reaches the kiln.

Core tools:
- Reverse shrinkage: enter a finished target size and get the wet size to throw.
- Forward shrinkage: enter a wet size and estimate the fired size.
- Batch Board: plan repeatable sets with count, clay body, finished target, wet dimensions, tolerance band, clay reserve, shelf footprint, rough capacity, and copyable production notes.
- Volume Calculator: estimate fired capacity for mugs, bowls, cylinders, and rounded bowls in fl oz and mL.
- Test Bar: calculate measured shrinkage from fired test bars, including optional two-stage dry/fire shrinkage.
- Studio hub: cone reference, glaze recipe scaling, firing schedules, clay weight guide, and offline Studio Reference Pack.
- Clay library: built-in studio clay presets plus custom clay bodies.
- History: save local project calculations and notes.
- Unit support: inches with pottery-friendly fractions, plus centimeters.

Everything runs on device. Kilnshrink does not require an account, network connection, camera, microphone, location, contacts, or notifications. Saved projects, custom clay bodies, recipes, schedules, and preferences stay in local storage.


## Version history (last 5 releases)

### 2.1 — 2026-06-30

Version 2.1 adds Batch Board, a production planning tool for repeatable thrown sets. It calculates wet dimensions, clay reserve, shelf footprint, tolerance bands, rough capacity, readiness score, and copyable batch notes.

This release also adds a bundled Studio Reference Pack with ten offline sheets for shrinkage workflow, test bars, batch planning, capacity math, cones, glaze specific gravity, clay weights, firing schedules, inch fractions, and studio checklists.

### 2.0 — 2026-06-24

Kilnshrink 2.0 — a pro studio upgrade for potters, still 100% offline.

• Cone Reference: the full Orton cone chart (022–14) at two heating rates, plus a "what cone did I reach?" peak-temperature lookup.
• Glaze Recipes: build percentage recipes and batch-scale them to any gram target.
• Specific Gravity tool: measure SG from a sample and get the exact water to add.
• Firing Schedules: build ramp / hold / cool programs with total time, peak temp, and peak cone.
• Clay Weight Guide: the starting ball-of-clay weight for six thrown forms by size.
• Temperature and weight converters woven throughout.

No account, no network — everything stays on your device.

### 1.2 — 2026-06-17

Throwing Chart: turn your selected clay into a printable, shareable shrinkage reference card — common finished sizes beside the wet size to throw, with proper inch fractions, plus clay name, cone, and shrinkage %. Toggle finished->wet or wet->fired and export a crisp image to Photos, AirPrint, or Messages. Plus clearer error messages in Calculate and Volume.

### 1.1 — 2026-06-15

What's New in Kilnshrink 1.1

Volume Calculator (new tab)
Find out if your mug will hold 12 fl oz — before it goes in the kiln. Enter the inner diameter and height of your piece, pick your clay, and Kilnshrink tells you the fired capacity in fluid ounces and millilitres. Three vessel shapes: cylinder (mugs, vases), bowl (frustum), and rounded bowl (teabowl). Works from wet or already-fired dimensions. A benchmark band shows how your piece compares to espresso, small mug, standard (12 oz), large (16 oz), and tall mug (20 oz).

Test Bar (new tab)
Stop guessing your clay's shrinkage from a data sheet. Fire a 100 mm wet bar at your usual cone, measure the result, and enter both numbers. Kilnshrink computes your actual total shrinkage from the SHAB test-bar method. Optional two-stage mode separates drying and firing shrinkage. A family-range band shows where your result falls among raku, earthenware, stoneware, paper clay, and porcelain. Save the measured result straight to your clay library as a custom entry.

Fixes and polish
The onboarding walkthrough now mentions the Volume and Test Bar tools. Version display fixed to always read 1.1 (3).

### 1.0 — 2026-06-11

No release notes.

## More apps by Robert Corbin

- [Daily Word Journey](https://appshunter.io/ios/app/daily-word-journey/id6761548266)
- [Hush Secret Text](https://appshunter.io/ios/app/hush-secret-text/id6761658175)
- [Renew Guard](https://appshunter.io/ios/app/renew-guard/id6761755447)
- [Receipt to PDF](https://appshunter.io/ios/app/receipt-to-pdf/id6761782025)
- [Route Your Pay](https://appshunter.io/ios/app/route-your-pay/id6761783719)
- [Tip Arbiter](https://appshunter.io/ios/app/tip-arbiter/id6761786879)

All apps by Robert Corbin: https://appshunter.io/developer/1890247992

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-14.*