Mouth ulcers typically take about 1 to 2 weeks to heal on their own without treatment. Most minor ulcers heal within this timeframe, usually resolving within 10 to 14 days

. The healing duration can vary depending on the type of ulcer:

• Minor (simple) canker sores: Usually heal within 1 to 2 weeks

• Major canker sores: These are larger and deeper, may take several weeks up to 6 weeks to heal, and can sometimes leave scars

• Herpetiform ulcers: Clusters of tiny sores that may take 2 to 4 weeks to heal

While there is no way to speed up the healing process significantly, symptom management such as avoiding irritating foods, using soft toothbrushes, rinsing with salt water, and applying topical treatments can help reduce pain and discomfort during healing

. If a mouth ulcer lasts longer than 3 weeks or is unusually painful, recurrent, or accompanied by other symptoms, it is advisable to see a healthcare professional as it may indicate a more serious condition

. In summary, most mouth ulcers heal within 1 to 2 weeks, but larger or more severe ulcers can take several weeks to fully resolve.