How Much Vest Do You Need? A Capacity Guide

Vest capacity is quoted in litres, which is honest but unhelpful: nobody pictures a litre. Here's the translation we use across the counter.

Around 5–6 litres: race day

Bottles up front, gels, a light jacket, phone, and not much else. This is the racing end of the range (think Ultimate Direction's Race Vest) for supported events where aid stations carry the bulk. It disappears on your back, which is the point.

10–12 litres: the long-day workhorse

The size most NZ trail runners actually need. New Zealand events routinely mandate a seam-sealed jacket, thermal layers, hat and gloves, first aid and an emergency blanket, and on a cold forecast the required list grows. A 10–12 L vest like the Ultra Vest swallows full mandatory kit with food and 1–2 litres of fluid, and still cinches down tight when it's half empty. If you're only buying one vest for training and racing here, buy this size.

15 litres and up: all-day and overnight

Adventure Vest territory and beyond into fastpacks: unsupported missions, big winter days, hut trips where you're carrying real food and real layers. You trade a little racing snugness for the ability to carry your whole day.

Capacity is nothing without fit

A vest that bounces is either the wrong size or badly adjusted, usually adjustment. Weight rides best split front and back, bottles forward. Our earlier guide, The Running Vest, Explained, covers fitting in detail. Every pack page here lists volume with a plain-English line under it, and Gear Compare puts volumes, load systems and pocket layouts side by side.

Bring your race's mandatory kit list into the showroom and we'll pack it into a vest in front of you. The fastest way to know your size is to see your gear inside it.