Comparison

Ratio vs Combustion Inc.

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Ratio

This app helps you master cooking by understanding fundamental ingredient relationships. It calculates ingredient amounts based on ratios, freeing you from strict recipes and allowing for creative variations. Explore 32 critical culinary ratios with instructions, variations, and tools to store and share your own creations.

Highlights
  • 32 critical culinary ratios
  • Ingredient amount calculator
  • Ounces-to-grams converter
  • Recipe variations and ideas
  • Store custom recipes and notes
  • Share creations on social media
Features
Currently charting
Read full description

Free yourself from recipes! The best-selling cookbook, Ratio: The Simple Codes Behind the Craft of Everyday Cooking, by me, Michael Ruhlman, is now an iPhone app that will help you calculate amounts of ingredients in all the fundamental culinary preparations. When you know a ratio, you don’t know a recipe, you know 1,000. And this application does all the calculating for you. “Cooking, like so many other creative endeavors is defined by relationships. For instance, knowing exactly how much flour to put into a loaf of bread isn’t nearly as useful as understanding the relationship between the flour and the water, or fat, or salt. That relationship is defined by a ‘ratio’ and having a ratio in hand is like having a secret decoder ring that frees you from the tyranny of recipes. ….Michael Ruhlman, in handing us mortals a power better suited to the gods, has changed the balance of kitchen power forever.” —Good Eats host Alton Brown What You Get: --THE 32 CRITICAL RATIOS that form the backbone of the culinary arts, with instructions: doughs, batters, meat preparations, custards, sauces (pasta dough and pizza dough, sponge cake and pancakes, fritters and crepes, stocks and sauces, crème caramel and chocolate sauce. --A CALCULATOR that figures out how much of each ingredient you need, no matter how many or how few people you want to serve. --An OUNCES-TO-GRAMS CONVERTER (ratios work no matter what unit you choose to use!). --DELICIOUS VARIATIONS FOR RECIPES on all the ratios, ideas for the creation of new dishes according to your tastes. --An easy way to STORE YOUR OWN RECIPES and notes that you’ve created from the basic ratios. --Quick fun ways to SHARE what your cooking with your fellow cooks, on Facebook and on Twitter. --Ratios is also a great way to understand and TWEAK YOUR OWN RECIPES, to help you make your pancakes even fluffier, your pizza dough crisper, your crème brulee richer.

About

Combustion Inc.

Monitor and graph real-time food temperatures during cooking. Predict exactly when your meal will be ready using advanced sensor data and a predictive engine. Receive alerts for key cooking events and ensure food safety.

Highlights
  • Real-time core, surface, and ambient temperature graphing
  • Predictive engine for exact 'ready' time estimation
  • Advanced alerts for cooking events
  • Food safety parameter setting
  • Firmware updates for accessories
  • Cloud connectivity for remote monitoring
  • Live Activity and Apple Watch support
Features
Read full description

See (and graph!) exact temperatures throughout your food while it cooks. Know exactly when it will be done. View and graph core, surface, and ambient temps in real time. The wireless Predictive Thermometer was built to answer a simple but important question: when will my food be ready? Combustion’s Predictive Engine™ estimates exactly when that will be, using the data from 8 onboard sensors (the most of any cooking thermometer). Important firmware updates! The Combustion App includes the latest firmware updates for Predictive Thermometers and other Combustion Accessories including Boosters, Displays, Giant Grill Gauges and other forthcoming products. Firmware updates improve core functions including time-to-cook predictions, longer battery life, and can add new features. MeatNet™ Cloud – for functionally unlimited range! Use with WiFi Accessories or with a second mobile device to stream your cook data to the cloud. Watch your cook in real-time from anywhere with internet access. Live Activity/Apple Watch support. The Combustion App works with iOS as well as iPadOS and MacOS (M1 or newer). Includes Live Activity (Dynamic Island) display feature so you can watch key temps even when the app is in the background. So handy! Combustion App Features: – Set target temp: so that your food comes out just the way you want it – See predictions in relative time (“ready in” countdown) or in absolute “clock” time – See key temps in real-time: including TrueCore®, TrueSurface™, TrueAmbient™ – Get notifications for important cooking events with advanced alerts (ready alarm, 5-minute warning, disconnect alert, low battery notification) – Set SafeCook™ parameters (integrated food-safety) – Know exactly when your food is safe to eat – Set-up WiFi connectivity for Combustion WiFi accessories – Graph your food’s temperatures in real-time! – See (and graph) temperatures from all 8 sensors with Advanced Cooking Mode – Enables multi-node MeatNet™: use any combination of Combustion accessories to extend Bluetooth signal range + strength – Use with or without Combustion Display – Export cooking data - to fine-tune your technique – Update firmware: get better performance and new features for Combustion tools – Works with most cooking appliances and cookware types – Works with all kinds of foods and most cooking appliances - BBQ smokers, ovens, ranges, grills, and more - indoors and out. – Works with or without WiFi Get more consistent results with all your favorite foods: steak, pork chops, brisket, pork shoulder, roasts, turkey, whole chicken, ribs, fish, bread, and more. Advanced graphing on the Combustion App helps you visualize exactly how heat moves through your food. You will understand the relationship between ambient cook temps and surface temps. And how surface temps really control how long things take – and how evenly food cooks. It may shock you to find out the oven temp (or grill temp) you set is not the same as the food is actually experiencing! The Combustion Inc app puts all that knowledge in front of you – with instant feedback, so you’re not just cooking better, you’re also learning as you go. And learning has never been so delicious.

Screenshots

Ratio4 screens
Combustion Inc.4 screens

Verdict

The call

The clearest difference is price: Combustion Inc. at Free against Ratio's $4.99. Combustion Inc. also leads on rating (4.7 vs 4.3) and review sentiment (76% vs 49%). Ratio's advantage is chart position (#49 vs unranked) and iOS requirement (10.0 vs 16.0). On update cadence, ads, in-app purchases and device support there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Combustion Inc. is free to download; Ratio costs $4.99 up front. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

Combustion Inc. holds the better App Store score, 4.7 against 4.3. That said, the two scores are not equally well evidenced: Combustion Inc. has 1.9K ratings behind it against 16, so its average is the more settled of the two. Written reviews point the same way: 49% of Ratio's written reviews are positive against 76% of Combustion Inc.'s.

UpkeepUpdate frequency

Ratio ships an update every 2 months, Combustion Inc. every 6 weeks. Both last shipped on October 20, 2026.

Scorecard7 real differences · 4 level
Ratio versus Combustion Inc.: the parameters behind the verdict, then further details
ParameterRatioCombustion Inc.
Price$4.99Free — better
Rating4.3 (16 ratings)4.7 (1.9K ratings) — better
Positive reviews48.9% of reviews76.3% of reviews — better
Number of ratings161.9K — better
Update frequencyEvery 2 monthsEvery 6 weeks — better
AdsNoNo
In-app purchasesNoNo
MonetizationPaidFree — better
Best chart rank#49 — better—
DevicesiPhone, iPodiPhone, iPad
Requires iOS10.0 — better16.0
Further details — not scored
Size7 MB119 MB
Age rating4+4+
DeveloperRuhlman Enterprises, Inc.Combustion Inc.

Customer experience

Ratio

All ratings16 ratings
Positive81.3%
Neutral6.3%
Negative12.5%
Written reviews94 reviews
Positive48.9%
Neutral14.9%
Negative36.2%

Combustion Inc.

All ratings1,858 ratings
Positive93.7%
Neutral1.7%
Negative4.6%
Written reviews80 reviews
Positive76.3%
Neutral3.8%
Negative20.0%

Bugs and requests

Ratio

Not enough reviews yet to summarise bugs or requests.

Combustion Inc.

Reported bugs

5 issues
  • Thermometer disconnects during use
  • App unable to stop timer
  • Inaccurate temperature readings
  • App unable to find device
  • Firmware update issues

Requested features

5 requests
  • Cooking history and logging
  • Live status widget
  • Apple Watch and Dynamic Island support
  • Ambient temperature alerts
  • Customizable probe labeling

In-app purchases

None

Ratio

No in-app purchases

None

Combustion Inc.

No in-app purchases

Questions

Is Ratio free?
Ratio costs $4.99, with no in-app purchases.
Is Combustion Inc. free?
Combustion Inc. is free to download, with no in-app purchases.
Which has better reviews, Ratio or Combustion Inc.?
Combustion Inc. is rated higher. Ratio averages 4.3 out of 5 from 16 ratings, while Combustion Inc. averages 4.7 from 1.9K ratings.
Do Ratio or Combustion Inc. have ads?
Neither Ratio nor Combustion Inc. shows ads.
Which is updated more often, Ratio or Combustion Inc.?
Ratio ships an update every 2 months, and Combustion Inc. every 6 weeks. Most recently, Ratio was updated on October 20, 2026 and Combustion Inc. on October 20, 2026.

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