A sagging or overly soft mattress can lead to poor sleep, back pain, and discomfort. While replacing your mattress is the best long-term solution, there are several effective ways to firm up your current mattress without buying a new one.
In this guide, we’ll explore six proven methods to make your mattress firmer, backed by sleep science and expert recommendations. Whether you have a memory foam, innerspring, or hybrid mattress, these practical tips will help restore its firmness and support for better sleep quality.
1. Flip or Rotate Your Mattress
Why It Works
Over time, mattresses develop soft spots due to repeated pressure on certain areas. Flipping or rotating your mattress redistributes weight and extends its lifespan.
How to Do It:
- Flipping: If your mattress is double-sided, flip it every 3-6 months.
- Rotating: If it’s one-sided, rotate it 180 degrees every 3 months to even out wear.
Pro Tip: Check the manufacturer’s guidelines before flipping, as some modern mattresses are designed for one-sided use only.
2. Use a Firm Mattress Topper
Why It Works
While most mattress toppers are designed to add softness, latex or high-density foam toppers can increase firmness.
What to Look For:
- Material: Opt for latex or high-density memory foam for extra support.
- Thickness: A 2-3 inch topper adds noticeable firmness.
- Density: Look for a density of 4-5 lbs per cubic foot for the best results.
Pro Tip: Avoid plush mattress pads, as they make mattresses softer instead of firmer.
3. Lower Your Room Temperature
Why It Works
Memory foam mattresses react to temperature changes—warmer rooms make the foam softer, while cooler temperatures keep it firmer.
How to Do It:
- Set your thermostat to 60-67°F (15-20°C) at night.
- Use breathable cotton or linen bedding to prevent overheating.
- Place a fan near the bed to improve airflow and mattress cooling.
Pro Tip: This method works best for memory foam and hybrid mattresses with foam layers.
4. Place Plywood Under Your Mattress
Why It Works
A sagging bed frame or box spring can reduce support. Adding a plywood board underneath strengthens the base and makes the mattress feel firmer.
How to Do It:
- Measure your bed frame and cut plywood to fit.
- Place a ½-inch thick board between the mattress and the base.
- Sand the edges of the plywood to prevent damage to your mattress.
Pro Tip: Use breathable fabric over the plywood to prevent moisture buildup.
5. Expose Your Mattress to Sunlight
Why It Works
Humidity can soften mattress materials over time. Placing your mattress in the sun for a few hours helps remove excess moisture, which restores firmness and eliminates bacteria.
How to Do It:
- Move your mattress outside for 3-6 hours on a sunny day.
- If outdoor space isn’t available, open windows and use a dehumidifier.
Pro Tip: This method works especially well for foam and latex mattresses.
6. Check Your Mattress Trial or Warranty
Why It Works
Many mattress brands offer trial periods and warranties, allowing you to exchange or return a mattress if it becomes too soft prematurely.
What to Do:
- Check the manufacturer’s website for warranty details.
- If your mattress is within a 100-night trial period, contact customer support for an exchange.
- Some brands provide firmness adjustment kits for customers.
Pro Tip: If none of the above solutions work, consider upgrading to a firmer mattress suited to your sleep style.
Final Thoughts: Should You Buy a New Mattress?
If your mattress is more than 7-10 years old, has deep sags, or doesn’t respond to these fixes, it may be time for a replacement. Investing in a high-quality mattress ensures better sleep, spinal alignment, and long-term comfort.
Top Firm Mattress Picks for 2025:
- Best Budget Firm Mattress: Nectar Hybrid Firm
- Best Luxury Firm Mattress: Saatva Classic Firm
- Best Eco-Friendly Firm Mattress: Avocado Green Mattress
Frequently Asked Questions (FAQs)
Mattresses naturally lose firmness due to body weight, material breakdown, and humidity exposure. Regular rotation and maintenance can help prolong firmness.
Try lowering your room temperature, using a firm mattress topper, or placing plywood under the mattress for extra support.
For back and stomach sleepers, a firmer mattress reduces spinal misalignment and improves sleep posture. However, side sleepers may need a medium-firm mattress for pressure relief.
Pillow-top mattresses are designed for softness, but you can try:
Using a latex topper for added support.
Placing plywood under the mattress.
Removing the pillow-top layer (if possible).
If your mattress is over 7 years old, has visible sagging, or causes discomfort even after trying these methods, it’s time for a replacement.
Summary: Quick Fixes for a Firmer Mattress
| Solution | Effectiveness | Best For |
|---|---|---|
| Flip or Rotate | ⭐⭐⭐⭐ | All mattress types |
| Firm Mattress Topper | ⭐⭐⭐⭐⭐ | Memory foam & hybrid mattresses |
| Lower Room Temperature | ⭐⭐⭐ | Memory foam mattresses |
| Use Plywood Underneath | ⭐⭐⭐⭐ | Sagging mattresses |
| Expose to Sunlight | ⭐⭐⭐ | Humid environments |
| Check Warranty/Trial | ⭐⭐⭐⭐⭐ | Newer mattresses |
By following these six simple steps, you can extend the life of your mattress and enjoy a more supportive sleep surface. If these fixes don’t work, consider investing in a high-quality firm mattress for long-term comfort.