How much can thermal curtains reduce heating costs?

Windows can account for up to 30% of a home's heat loss — quality thermal curtains can meaningfully reduce that, especially on older or single-pane windows.

Do thermal curtains work in summer too?

Yes — the same insulating layers that keep heat in during winter also block outside heat and sunlight in summer, helping reduce AC use.

Can thermal curtains be machine washed?

Most are machine washable on a gentle cold cycle — always check the care label, and avoid high heat drying, which can damage the blackout lining.

Best Thermal Curtains of 2026

Thermal curtains add a genuine layer of insulation against a window — one of the largest sources of heat loss in a room — while also blocking light and reducing outside noise as a bonus.

We compared blackout percentage, panel size options, and grommet-style hanging ease, since the right size and hardware compatibility matters as much as the insulating fabric itself.

What to Look For

Blackout percentage: 100% blackout blocks the most light and provides the best insulation; lower percentages still help but let some light through.
Fabric layers: Triple-weave blackout fabric with a felt or foam liner insulates noticeably better than a single-layer curtain.
Panel size: Measure your window width and add a few inches on each side for panels to fully close without gaps.
Noise reduction: Heavier thermal fabric doubles as sound dampening — worth prioritizing if your bedroom faces a noisy street.

Our Top Picks

#1 Best Overall

NICETOWN Thermal Insulated 100% Blackout Curtains

100% blackout with a felt fabric liner for dust isolation and noise reduction, full light blocking panels.

~$35 View on Amazon →

#2 Best Value

LEMOMO Blackout Curtains, 52 x 84 Inches

Set of 2 thermal insulated room-darkening panels sized for standard bedroom windows.

~$30 View on Amazon →

#3 Best for Smaller Windows

NICETOWN Black Blackout Curtains, 42" x 63"

Solid grommet thermal insulated drapes designed for kitchen and smaller window treatments.

~$25 View on Amazon →

#4 Best for Tall Windows

H.VERSAILTEX 100% Blackout Curtains, 96" Long

Extra-long thermal insulated panel built for patio doors and floor-to-ceiling windows, energy saving grommet design.

~$32 View on Amazon →

Bottom Line

The NICETOWN 100% blackout curtains are the most complete pick for insulation, light blocking, and noise reduction together. Match panel length to your specific window before ordering — that's the detail most likely to cause a return.