Recipe Scaler Calculator
Scale any recipe up or down instantly. Adjust serving sizes with automatic ingredient calculations and UK unit conversions.
Servings
Ingredients
UK Baking Conversions Table
Essential conversions for UK recipes using metric and imperial measurements.
| Ingredient | 100g | 1 Cup (US) | 1 Tbsp |
|---|---|---|---|
| Plain Flour | 100g | 120g | 8g |
| Self-raising Flour | 100g | 120g | 8g |
| Caster Sugar | 100g | 200g | 13g |
| Icing Sugar | 100g | 120g | 8g |
| Butter | 100g | 227g | 14g |
| Cocoa Powder | 100g | 85g | 6g |
| Rolled Oats | 100g | 90g | 6g |
| Ground Almonds | 100g | 95g | 6g |
| Honey / Golden Syrup | 100g | 340g | 21g |
| Milk (whole) | 97ml | 240ml | 15ml |
Unit Converter
Standard Serving Sizes Guide
| Food Type | Standard Serving | Notes |
|---|---|---|
| Pasta (dry) | 75-100g per person | Doubles when cooked |
| Rice (dry) | 75g per person | ~150g cooked |
| Chicken breast | 150-200g per person | Raw weight |
| Beef mince | 125-150g per person | Raw weight |
| Fish fillet | 150g per person | Boneless |
| Soup | 300-400ml per person | As starter |
| Cake (sponge) | 1/8 to 1/10 of 20cm tin | Standard slice |
| Salad leaves | 60-80g per person | Side salad |
How to Scale a Recipe: Complete Guide
Whether you're cooking for a dinner party of 20 or scaling down your grandma's famous cake to serve just two, recipe scaling is an essential kitchen skill. The basic principle is straightforward: divide each ingredient by the original serving count and multiply by your desired count. However, there are some important nuances to understand for perfect results every time.
The Scaling Formula
The conversion factor is simply: New Servings ÷ Original Servings. If a recipe feeds 4 and you want to feed 10, your factor is 2.5. Every ingredient quantity is multiplied by 2.5. Simple in principle, but precise execution matters.
Ingredients That Don't Scale Linearly
Some ingredients behave differently at scale. Salt, spices, and leavening agents (baking powder, bicarbonate of soda) should not be doubled blindly. When doubling a recipe, start with 1.5x the seasoning and adjust to taste.
Baking powder in particular: too much causes a metallic taste and structural collapse. A general rule is to use 75% of the scaled amount for leavening agents when scaling up significantly.
Cooking Time Adjustments
Cooking time is one of the most misunderstood aspects of recipe scaling. Time does not scale with quantity. When you double a batch of cookies, you don't bake them for double the time - you may need just 2-3 extra minutes.
The reason is that heat penetration depends on the thickness of the food, not its total mass. For large roasts, the rule of thumb is 20 minutes per 450g plus 20 minutes extra. For baking, the same pan-size recipe takes the same time regardless of batch count (you simply bake more batches).
Pan Size Matters
When scaling baked goods, pan size is crucial. A doubled cake batter in the same tin will be too deep and bake unevenly. As a guideline: doubling a recipe means using a pan with double the area (not double the diameter).
A 20cm round tin has an area of ~314cm². To double, you'd need two 20cm tins or one approximately 28cm tin.
UK vs US Measurements
UK and US cup sizes differ. A US cup is 240ml; an Australian cup is 250ml. UK recipes rarely use cups - they prefer weights, which are far more accurate.
If converting from a US recipe, always convert cups to grams using our conversion table above. For liquids, 1 US cup = 240ml. For flour, 1 US cup = approximately 120g of plain flour.
Spice and Seasoning Scaling Tips
For spices: scale to 75% when multiplying by 3 or more. For salt: scale to 80% and taste as you go. For vanilla extract: scale to 75% as it can become overpowering.
For chilli and strong spices: start at 60% of scaled amount. For fresh herbs: these can usually be scaled at 100% or even reduced slightly at large scales.
Related Calculators
For temperature conversions when following recipes, use our Oven Temperature Converter. For additional unit conversions between metric and imperial, visit our Unit Converter.
How to Convert Recipe Scaler
This converter provides instant, accurate results for your measurement conversions. The UK uses a mix of metric and imperial measurements in daily life, which can make conversions a frequent necessity. Road signs use miles, food is sold in grams and kilograms, and height is often quoted in feet and inches despite the metric system being the official standard.
Understanding the conversion formula helps verify results and perform quick mental calculations when a tool is not available.
Key Information
Common UK conversion factors: 1 inch = 2.54 cm, 1 foot = 30.48 cm, 1 mile = 1.609 km, 1 pound (lb) = 0.4536 kg, 1 stone = 6.35 kg, 1 pint (UK) = 568 ml, 1 gallon (UK) = 4.546 litres, 1 acre = 0.4047 hectares. Temperature conversions use the formula: Celsius = (Fahrenheit - 32) x 5/9.
Example Calculation
To convert 5 feet 10 inches to centimetres: first convert to total inches (5 x 12 + 10 = 70 inches), then multiply by 2.54 to get 177.8 cm. For weight, a person weighing 12 stone 7 lbs is 12.5 stone, which equals 79.4 kg (12.5 x 6.35).
Source: Based on international measurement standards. Last updated March 2026.
Frequently Asked Questions
How does the recipe scaler calculator work?
Does cooking time scale with the recipe?
How many cups is 100g of butter in UK recipes?
How do I convert cups to ml for UK recipes?
Can I scale a recipe to feed 50 or more people?
What units does the recipe scaler support?
Are the ingredient amounts rounded sensibly?
Official Sources
Data verified against official UK government sources. Last checked April 2026.