9 Low-Calorie, Low-Carb, & Sugar-Free Sonic Drinks

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At Sonic, there are many options to get you a low-calorie, low-carb, and sugar-free drink without any of the guilt and all of the flavor. 

Sonic has 6 main categories of beverages that you can choose from. 

To learn more about the lower-calorie options in each of these categories, click on any of the links below:

Overview of Low-Calorie, Low Carb, Low Sugar Drinks At Sonic

Coca Cola Zero000
Diet Coke000
Sprite ZERO000
Diet Dr. Pepper000
Diet Limeade1010
Diet Cherry Limeade2032
Unsweet Iced Tea000
Green Mountain Coffee000

What Is Considered A Low-Calorie Drink At Sonic? 

Here are the criteria we used for determining what is a low-calorie drink at Sonic: 

  • Soft Drinks: 20 calories or less 
  • Slushes: There are no low-calorie Slushes (read more below)
  • Lemonades & Limeades: 25 calories or less
  • Iced Teas:25 calories or less
  • Coffee:10 calories or less
  • Add-ins: 25 calories or less

What Makes A Low Carb & Sugar-Free Beverage At Sonic?

To get a drink that falls into these categories, you will need to order something using diet or ZERO soda as a base and sugar-free add-ins or real fruit add-ins.  

The diet and ZERO sodas as well as sugar-free add-ins use artificial sweeteners to give it flavor.  This is usually aspartame and acesulfame potassium (ace-K).  

You could also do this with the Unsweetened Iced Tea and the Diet Limeade (The Diet Limeade does contain 10 calories and 1 gram of carbohydrate, but has no sugar).

Since there is no sugar added, this is what is going to keep the carbohydrates, and in turn, the calories down for you.

In addition to this, the Green Mountain Coffee that is served at Sonic contains zero calories when it is served black. You can add a bit of sweetness to your coffee without any calories or sugar by adding a packet of Sweet & Low.

What Increases Calories In A Drink At Sonic?

Full Sugar Drinks

Ordering full sugar drinks includes all non-diet or Zero sodas, iced tea, classic lemonade, and limeade drinks. 

Flavor & Candy Add-Ins

Unlike many other fast food restaurants, at Sonic you have the option to add different flavor shots to your beverages to customize the taste of your drink.

If you are trying to watch your calories it is important to note that adding in full sugar flavor add-ins or candy add-ins will increase calories by 45 calories to 210 calories per serving.  

If you want to try some of the add-ins, try a sugar-free flavor add-in, as these will decrease the added calories to 5 calories to 25 calories per serving (more on this below).

Low-Calorie Sonic Soft Drinks

Check out more healthy fast food options, including low calorie food/drinks and comparisons.

1. Coca-Cola ZERO

Sonic Coca-Cola ZERO

A zero calorie, zero sugar soda option that can be transformed by adding sugar-free flavor add-ins.

SizeCalsCarbs (g)Sugar (g)

Pro Tip: Try adding Diet Cherry flavor Add-in.  This will only increase your calories to 5 calories total per serving.  You can get fancy and add a cherry fruit on top for an additional 10 calories, keeping your total drink calories to 15 calories total.

2. Diet Coke

If you prefer the flavor of Diet Coke over Coke Zero, this is another option for you to keep calories down.

Diet Coke
SizeCalsCarbs (g)Sugar (g)

Pro Tip: Add lime fruit to your Diet Coke to increase the citrus flavor without the calories.

3. Sprite ZERO

Sonic Sprite ZERO

A lemon and lime flavored soda to help you quench your thirst.  

SizeCalsCarbs (g)Sugar (g)

Pro Tip: Swap this as the option you select for any of the limeade beverages at Sonic in order to decrease calories, carbs, and sugar from Sprite that has 100-350 calories per serving.  You can also add a sugar-free Blackberry flavor to your Sprite ZERO, only increasing calories by 5.

4. Diet Dr. Pepper

Sonic Diet Dr. Pepper

The guilt-free option is perfect for a cherry flavored treat.

SizeCalsCarbs (g)Sugar (g)

Pro Tip: Add some cherry fruit for added cherry flavor (10 calories each) or some additional cherry flavor with the Sugar-Free Cherry flavor add-in. 

Low-Calorie Sonic Slushes

Unfortunately, none of the Slushes that Sonic offers fall under the low-calorie, low-carb, and low sugar category. 

In fact, most of these drinks contain around 300 calories, all of which come from sugar. 

If you are trying to choose the lowest calorie Slush, I recommend going for the Peach Slush which contains the least amount of calories (250 calories in a medium size) and 66 grams of carbs (all from sugar)

If you choose the smallest size (a mini) then you reduce your consumption down to 120 calories and 32 grams of sugar.

If you want something sweet and cold with a slush-like consistency, check out the low-calorie limeades below.

Low-Calorie Sonic Lemonades & Limeades

5. Diet Limeade

Sonic Diet Limeade

Sonic’s signature Limeade drink made with Sprite ZERO and freshly squeezed lime over ice.

SizeCalsCarbs (g)Sugar (g)

Pro Tip: Add Sugar-Free Raspberry Flavor Add-in fo an additional 5 calories per serving to add a little flair to your next Diet Limeade.

6. Diet Cherry Limeade

A satisfying limeade made with real lime and diet cherry flavor in a Sprite ZERO base keeping your carbs and calories down.

SizeCalsCarbs (g)Sugar (g)

Pro Tip: Skip the Cherry fruit if you’d like to keep the calories down to a minimum (10 calories per cherry fruit) and increase the amount of fresh lime fruit added instead.

Iced Teas

7. Unsweet Iced Tea

Sonic Unsweet Iced Tea

This is a freshy brewed unsweet tea that is served over Sonic’s signature mini ice cubes.

SizeCalsCarbs (g)Sugar (g)

Pro Tip: Sweeten your tea up yourself by adding a sugar-free flavor add-in. My favorite include adding in Sugar-Free Peach (0 calories) or Sugar-Free Mango (5 calories).  You can also simply add lemon fruit to your iced tea if you prefer an unsweet tea.

Low-Calorie Sonic Coffee

8.  Green Mountain Brewed Coffee

Sonic uses 100 percent Green Mountain Arabica Beans for its brewed coffee.

SizeCalsCarbs (g)Sugar (g)

Pro Tip: You can add a bit of sweetness to your coffee by adding in a Sweet & Low Packet. You can also enjoy your black coffee on ice instead of hot.

Other Low Calorie Sonic Drinks

9.  Water (With Low-Calorie Add-in)

Water (With Low-Calorie Add-in)

While plain water might not seem like anything special, remember that Sonic offers sugar-free and low-calorie flavor add-ins to its beverages. This means that you could potentially take your plain water and flavor it in a variety of different ways. 

For example, you could add the Blue Coconut Flavour that Sonic offers to your ice water for only 25 calories. Another option that would only add around 20 calories is the Blue Raspberry flavor.

If you would rather not have any added sugar or calories, you could try one of the sugar-free add-ins in your water such as the Blackberry or the Peach flavor. With this option, you would only be adding around 5 calories to your water at most.

If you would rather stay away from artificial sweeteners, try adding real fruit options like lemon or lime (for 5 calories) or cherry (for 10 calories).

Tips For Ordering Low-Calorie Drinks At Sonic

tips for ordering low calorie drinks at sonic

Use Sugar-Free flavor Add-Ins

Sonic offers some great options for adding sugar-free flavor to your drinks in order to keep calories down.  

When ordering a medium, sugar-free flavor add-ins may add anywhere from 0-20 calories per serving.

Here are my top picks for sugar-free add-ins: 

  • Blackberry Sugar-Free Add-in (5 calories)
  • Diet Cherry Sugar-Free Add-in (20 calories)
  • Lemon Add-In (5 calories)
  • Lime Add-In (5 calories)
  • Peach Sugar-Free Add-in (0 calories)
  • Raspberry Sugar-Free Add-In (5 calories)

Avoid RT 44 sizes

Ordering an RT 44 size (which is 44 ounces of liquid) will increase your caloric intake since it is the biggest size they offer.  

Pro tip: You can always ask for easy ice in a small or medium if you would like to increase the volume of drink slightly you are getting in your cup without sizing up.

Choose Diet or ZERO Soda Options As Your Base

To keep calories and carbs down, order a diet soda such as Diet Dr.Pepper or Diet Coke, or a ZERO option soda such as Coca-Cola ZERO or Sprite ZERO.  

All of these drinks are zero calories and zero carbs as well as sugar-free.  

Adding a sugar-free flavor add-in will give you additional flavor, as well while still keeping the carbs and calories to a minimum.

Add Lemon and Lime Fruit For Added Flavor

Instead of adding more flavor add-ins, choose lemon and/or lime fruit instead.  It will offer a crisp and refreshing citrus flavor without adding any sugar to your drink.

For example, you could add in a squeeze of lime fruit to your Diet Coke to give it a different flavor for only 5 extra calories. 

If you wanted to avoid artificial sweeteners at Sonic but still keep your drink low calorie and low carb, you could order a regular water and flavor it with a squeeze of real lemon.

Frequently Asked Questions

Does Sonic Have Sugar Free Slushies? 

No, Sonic does not offer any sugar-free Slush options. While you can choose to add sugar-free add-in flavors to your slushy, the base will still contain sugar.

In fact, a small-size Peach Slush (the lowest calorie Slush option) still contains 180 calories, all of which come from a hefty 48 grams of sugar.

Are There Sugar-Free Syrups At Sonic? 

Yes, Sonic does offer sugar-free add-ins to flavor your beverage. The sugar-free add-ins that Sonics offers include Blackberry, Diet Cherry, Mango, Peach, and Raspberry Flavour. You can also choose real fruit options such as lemon or lime for around 5 extra calories.

Other Low-Calorie Fast Food Drinks

About The Author

Caryn Watt

Caryn Watt is a certified personal trainer & nutrition coach. Working primarily with women all over the world, she focuses her time on helping clients learn more about nutrition and the importance of improving their relationship with food through tracking macros, movement, and mindfulness.

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