Gel Comparison

Best Race Day Gels Ranked by Carbs Per Dollar (2026)

FuelCenter Team·March 30, 2026·8 min read

Marathon runners spending $15-25 on gels per race day face significant cumulative costs during training blocks. We ranked 7 popular gels by carbs-per-dollar value, carb density, and real-world usability.

Why Carbs Per Dollar Matters

Modern fueling targets 90-120g carbs per hour rather than the older 30-45g guidance. A 4-hour marathon at 90g/hr requires 360g total carbs. That's 16 standard GU gels at $2.20 each, or $35 per race. Training twice weekly for 16 weeks? Over $1,100 on gels alone.

The difference in value is dramatic: Maurten Gel 100 delivers 6.3g carbs per dollar, while Carbs Fuel delivers 25.0g per dollar, roughly 4x the purchasing power.

Head-to-Head Comparison

GelPriceCarbsCarbs/$WeightCaffeine
Carbs Fuel$2.0050g25.0~75gNo
SiS Beta Fuel$3.4940g11.560gNo
GU Energy Gel$2.2022g10.032g0-40mg by flavor
Precision PF 30$3.1230g9.660gCaf version (100mg)
Maurten Gel 160$5.5040g7.360gNo
Maurten Gel 100$4.0025g6.340gCaf 100 version (100mg)

* SiS Beta Fuel is occasionally sold at $1.00/gel through The Feed promotions.

Individual Gel Reviews

SiS Beta Fuel

Best value high-density gelGreat for ultras

40g carbs at a 1:0.8 glucose-to-fructose ratio. Texture is thicker than isotonic gels but doesn’t require water. Flavors include Tropical, Apple, and Lemon,all mild. For a marathon at 90g/hr, you need 5-6 gels versus 16 GUs. The packet needs a firm squeeze to empty fully.

Maurten Gel 100

Best for sensitive stomachs

25g carbs with hydrogel technology (sodium alginate polymer). Zero flavoring, zero preservatives,tastes like lightly sweetened water. Firm, jello-like consistency. Requires 14+ gels for a marathon at 90g/hr. Known for its gut-friendly reputation at high intensity.

Maurten Gel 160

Best high-dose premium gel

40g carbs, same hydrogel technology as the Gel 100. Requires 6-8 gels for a marathon versus 14+ for the Gel 100. Still significantly more expensive than SiS Beta Fuel for the same carb density.

Precision PF 30

Good for first-timersSolid science brand

30g carbs with a 2:1 glucose-to-fructose ratio. Mild citrus flavor ("Original"). Non-syrupy, jelly-like texture. Caffeine-free base; caffeinated version delivers 100mg. Requires 9-10 gels for a 90g/hr marathon.

GU Energy Gel

Best for beginnersBudget half-marathon pick

22g carbs, 2:1 glucose-to-fructose ratio. Best-selling running gel for a reason,around since 1993. 20+ flavor options. Includes BCAAs and electrolytes. After mile 16, sweetness can become a challenge. Requires 14+ gels for a marathon.

Carbs Fuel

Best carbs per dollar,periodBest value ultra gel

50g carbs, highest carbs-per-dollar at 25.0. Liquid formula (not thick gel). Simple ingredients: water, maltodextrin, sucrose, fructose, citric acid, sodium. "Salted" version adds 450mg sodium per packet. Only available direct from carbsfuel.com. No caffeine version currently exists.

Best Gel for Each Scenario

Best Budget GelCarbs Fuel
Best Premium GelMaurten Gel 100 (Caf 100)
Best for UltrasSiS Beta Fuel or Carbs Fuel
Best for First-TimersGU Energy Gel
Best High-Carb + ValueSiS Beta Fuel
Best for Gut IssuesMaurten Gel 160

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Mixing Gel Brands Mid-Race

A smart strategy: use SiS Beta Fuel or GU for miles 1-18, then switch to Maurten Gel 100 or 160 for the final push. For ultras, use budget gels as base fuel and hold Maurten Caf 100s in reserve for when you need them most.

FAQ

How many gels do I need for a marathon?

At 90g carbs/hr for a 3:30 marathon, you need ~315g total carbs. After subtracting pre-race drink: ~275g from gels. That’s 12-13 GU gels, 7 SiS Beta Fuels, 11 Maurten Gel 100s, 7 Maurten Gel 160s, or 5-6 Carbs Fuels.

What’s the cheapest gel per gram of carbs?

Carbs Fuel at 25.0 carbs per dollar, followed by SiS Beta Fuel (11.5), GU Energy Gel (10.0), and Precision PF 30 (9.6).

Can I mix gel brands during a race?

Yes,and it’s often a smart strategy. Use SiS Beta Fuel or GU for early miles and switch to Maurten for the final push. Just don’t introduce a new brand on race day.

Is Maurten really worth the price?

For training, no. For race day,especially if you have a history of GI issues at high intensity,the premium may be justified. The Caf 100 version is particularly appealing for a late-race boost delivered in a stomach-friendly format.

What is the best gel for ultramarathons?

Cost per gram and flavor fatigue dominate. Carbs Fuel (50g, liquid, simple ingredients) and SiS Beta Fuel (40g, mild flavors) are top picks for ultras.

Do I need caffeine gels and when should I use them?

Aim for 3-6mg per kg of body weight. For a 70kg athlete, that’s 210-420mg,roughly 2-4 caffeinated gels. Save caffeine for the back half of the race.

Cody McCauley

Runner, builder of FuelCenter, and author of Surging. 5 marathons, 3:04 PR, currently chasing sub-3 at Copenhagen. More about FuelCenter →

Surging

A running newsletter on training, performance, and how progress compounds.

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