---
title: "How Many Gels for a Half Marathon? Calculator | TrainPace"
description: "Estimate how many gels you need for a half marathon. Use your finish time to get a carb target and a simple gel schedule."
url: https://trainpace.com/fuel/how-many-gels-for-half-marathon
---

# How Many Gels for a Half Marathon?

Estimate how many gels you need for a half marathon. Use your finish time to get a carb target and a simple gel schedule.

Most runners don't need a large gel load for a half, but 1-2 well-timed gels can make the last 5K feel much better.

- Gel estimate for your goal time
- Timing guidance
- Works with drink + gel combos

## How to estimate half marathon gel count

Use your goal time and intensity to decide whether you need gels and how many.

1. Enter goal time: Input your half marathon goal time.
2. Pick fueling approach: Decide gels-only or gels + sports drink.
3. Set timing: Use a steady schedule you practiced in training.

- [Calculate Half Marathon Gels](https://trainpace.com/fuel)

## Fueling reference

**Race-day carb targets and gel counts by finish time (baseline, no body weight entered)**

| Race | Finish time | Carbs/hour | Total carbs | Calories | Gels |
| --- | --- | --- | --- | --- | --- |
| Half marathon | 1:20 | 45 g/hr | 60 g | 240 kcal | 2 |
| Half marathon | 1:35 | 45 g/hr | 71 g | 284 kcal | 3 |
| Half marathon | 1:50 | 45 g/hr | 83 g | 332 kcal | 3 |
| Half marathon | 2:05 | 45 g/hr | 94 g | 376 kcal | 4 |
| Half marathon | 2:20 | 45 g/hr | 105 g | 420 kcal | 4 |
| Marathon | 2:50 | 75 g/hr | 213 g | 852 kcal | 5 |
| Marathon | 3:15 | 75 g/hr | 244 g | 976 kcal | 5 |
| Marathon | 3:45 | 75 g/hr | 281 g | 1124 kcal | 6 |
| Marathon | 4:15 | 75 g/hr | 319 g | 1276 kcal | 7 |
| Marathon | 4:45 | 75 g/hr | 356 g | 1424 kcal | 7 |
| Marathon | 5:15 | 75 g/hr | 394 g | 1576 kcal | 7 |

## Other TrainPace tools

- [Pace Calculator](https://trainpace.com/calculator) — training paces from a recent race result
- [VDOT Calculator](https://trainpace.com/vdot) — fitness score and equivalent race times
- [Training Plan Builder](https://trainpace.com/plan) — week-by-week 5K to marathon plans
- [Race Fuel Planner](https://trainpace.com/fuel) — carbs per hour and gel counts
- [Elevation Finder](https://trainpace.com/elevation-finder) — GPX route and climb analysis

## For AI agents

Every page on this site has a Markdown mirror at the same path with a .md suffix (for example /calculator.md), and honors an Accept: text/markdown request header on the HTML URL. The calculations here are also available as callable tools through a free public MCP server — no account or API key.

- [llms.txt](https://trainpace.com/llms.txt) — site index for agents
- [llms-full.txt](https://trainpace.com/llms-full.txt) — every page's Markdown in one file
- [MCP server docs](https://trainpace.com/mcp) — endpoint, tools, and client setup