diff --git a/.changeset/blue-places-guess.md b/.changeset/blue-places-guess.md
new file mode 100644
index 0000000000..1afcd215d2
--- /dev/null
+++ b/.changeset/blue-places-guess.md
@@ -0,0 +1,5 @@
+---
+"@sumup-oss/design-tokens": minor
+---
+
+Deprecated `--cui-icon-sizes-kilo`, `--cui-icon-sizes-mega`, `--cui-icon-sizes-giga`, and `--cui-icon-sizes-tera` in favour of new t-shirt-sized tokens that use `rem` units so that icons scale with the user's base font size (WCAG SC 1.4.4).
diff --git a/packages/circuit-ui/components/ActionMenu/components/ActionMenuItem.module.css b/packages/circuit-ui/components/ActionMenu/components/ActionMenuItem.module.css
index 90f2967d2b..d4a29892c0 100644
--- a/packages/circuit-ui/components/ActionMenu/components/ActionMenuItem.module.css
+++ b/packages/circuit-ui/components/ActionMenu/components/ActionMenuItem.module.css
@@ -10,7 +10,7 @@
 }
 
 .icon {
-  width: var(--cui-icon-sizes-mega);
-  height: var(--cui-icon-sizes-mega);
+  width: var(--cui-icon-sizes-m);
+  height: var(--cui-icon-sizes-m);
   margin-right: var(--cui-spacings-byte);
 }
diff --git a/packages/circuit-ui/components/Button/base.module.css b/packages/circuit-ui/components/Button/base.module.css
index 4def1d52f7..78a6234fbe 100644
--- a/packages/circuit-ui/components/Button/base.module.css
+++ b/packages/circuit-ui/components/Button/base.module.css
@@ -157,14 +157,14 @@
 }
 
 .trailing-icon {
-  width: var(--cui-icon-sizes-kilo);
-  height: var(--cui-icon-sizes-kilo);
+  width: var(--cui-icon-sizes-s);
+  height: var(--cui-icon-sizes-s);
 }
 
 /* Sizes */
 .s {
   --content-gap: var(--cui-spacings-bit);
-  --leading-icon-size: var(--cui-icon-sizes-kilo);
+  --leading-icon-size: var(--cui-icon-sizes-s);
   --loader-diameter: 4px;
   --loader-gap: 3px;
   --loader-transform: scale(150%);
@@ -176,7 +176,7 @@
 
 .m {
   --content-gap: var(--cui-spacings-byte);
-  --leading-icon-size: var(--cui-icon-sizes-mega);
+  --leading-icon-size: var(--cui-icon-sizes-m);
   --loader-diameter: 6px;
   --loader-gap: 5px;
   --loader-transform: scale(133%);
diff --git a/packages/circuit-ui/components/Field/Field.module.css b/packages/circuit-ui/components/Field/Field.module.css
index e41d1f1166..2d223cddea 100644
--- a/packages/circuit-ui/components/Field/Field.module.css
+++ b/packages/circuit-ui/components/Field/Field.module.css
@@ -95,8 +95,8 @@
   display: block;
   flex-shrink: 0;
   align-self: flex-start;
-  width: var(--cui-icon-sizes-kilo);
-  height: var(--cui-icon-sizes-kilo);
+  width: var(--cui-icon-sizes-s);
+  height: var(--cui-icon-sizes-s);
   margin-right: var(--cui-spacings-bit);
 }
 
@@ -124,7 +124,7 @@
 
 .s .validation-hint-icon {
   margin-top: calc(
-    (var(--cui-compact-s-line-height) - var(--cui-icon-sizes-kilo)) /
+    (var(--cui-compact-s-line-height) - var(--cui-icon-sizes-s)) /
     2
   );
 }
@@ -148,7 +148,7 @@
 
 .m .validation-hint-icon {
   margin-top: calc(
-    (var(--cui-body-s-line-height) - var(--cui-icon-sizes-kilo)) /
+    (var(--cui-body-s-line-height) - var(--cui-icon-sizes-s)) /
     2
   );
 }
diff --git a/packages/circuit-ui/components/Flag/Flag.module.css b/packages/circuit-ui/components/Flag/Flag.module.css
index 6133f9f160..165ad57f23 100644
--- a/packages/circuit-ui/components/Flag/Flag.module.css
+++ b/packages/circuit-ui/components/Flag/Flag.module.css
@@ -22,16 +22,16 @@
 }
 
 .s {
-  width: var(--cui-icon-sizes-kilo);
-  height: calc(var(--cui-icon-sizes-kilo) * 3 / 4);
+  width: var(--cui-icon-sizes-s);
+  height: calc(var(--cui-icon-sizes-s) * 3 / 4);
 }
 
 .m {
-  width: var(--cui-icon-sizes-mega);
-  height: calc(var(--cui-icon-sizes-mega) * 3 / 4);
+  width: var(--cui-icon-sizes-m);
+  height: calc(var(--cui-icon-sizes-m) * 3 / 4);
 }
 
 .l {
-  width: var(--cui-icon-sizes-giga);
-  height: calc(var(--cui-icon-sizes-giga) * 3 / 4);
+  width: var(--cui-icon-sizes-l);
+  height: calc(var(--cui-icon-sizes-l) * 3 / 4);
 }
diff --git a/packages/circuit-ui/components/Hamburger/Hamburger.module.css b/packages/circuit-ui/components/Hamburger/Hamburger.module.css
index 40ef3b08ef..4e62568774 100644
--- a/packages/circuit-ui/components/Hamburger/Hamburger.module.css
+++ b/packages/circuit-ui/components/Hamburger/Hamburger.module.css
@@ -10,13 +10,13 @@
 }
 
 .skeleton.s {
-  width: var(--cui-icon-sizes-kilo);
-  height: var(--cui-icon-sizes-kilo);
+  width: var(--cui-icon-sizes-s);
+  height: var(--cui-icon-sizes-s);
 }
 
 .skeleton.m {
-  width: var(--cui-icon-sizes-mega);
-  height: var(--cui-icon-sizes-mega);
+  width: var(--cui-icon-sizes-m);
+  height: var(--cui-icon-sizes-m);
 }
 
 .base {
@@ -59,14 +59,14 @@
 .base.s,
 .base.s::after,
 .base.s::before {
-  --hamburger-width: calc(var(--cui-icon-sizes-kilo) - 2px);
+  --hamburger-width: calc(var(--cui-icon-sizes-s) - 2px);
   --hamburger-offset: 5px;
 }
 
 .base.m,
 .base.m::after,
 .base.m::before {
-  --hamburger-width: calc(var(--cui-icon-sizes-mega) - 2px);
+  --hamburger-width: calc(var(--cui-icon-sizes-m) - 2px);
   --hamburger-offset: 7px;
 }
 
diff --git a/packages/circuit-ui/components/ImageInput/ImageInput.module.css b/packages/circuit-ui/components/ImageInput/ImageInput.module.css
index 491d44edf0..ab0582eccd 100644
--- a/packages/circuit-ui/components/ImageInput/ImageInput.module.css
+++ b/packages/circuit-ui/components/ImageInput/ImageInput.module.css
@@ -147,8 +147,8 @@
   top: calc(50% - 16px);
   left: calc(50% - 16px);
   visibility: hidden;
-  width: var(--cui-icon-sizes-giga);
-  height: var(--cui-icon-sizes-giga);
+  width: var(--cui-icon-sizes-l);
+  height: var(--cui-icon-sizes-l);
   color: var(--cui-fg-on-strong);
   pointer-events: none;
   opacity: 0;
diff --git a/packages/circuit-ui/components/Select/Select.module.css b/packages/circuit-ui/components/Select/Select.module.css
index 1eb11cc0e5..eda6c81e83 100644
--- a/packages/circuit-ui/components/Select/Select.module.css
+++ b/packages/circuit-ui/components/Select/Select.module.css
@@ -120,8 +120,8 @@ button.prefix,
 }
 
 .wrapper.s .icon {
-  width: var(--cui-icon-sizes-giga);
-  height: var(--cui-icon-sizes-giga);
+  width: var(--cui-icon-sizes-l);
+  height: var(--cui-icon-sizes-l);
   padding: var(--cui-spacings-byte);
 }
 
@@ -146,7 +146,7 @@ button.prefix,
 }
 
 .wrapper.m .icon {
-  width: var(--cui-icon-sizes-tera);
-  height: var(--cui-icon-sizes-tera);
+  width: var(--cui-icon-sizes-xl);
+  height: var(--cui-icon-sizes-xl);
   padding: var(--cui-spacings-kilo);
 }
diff --git a/packages/circuit-ui/components/SideNavigation/components/DesktopNavigation/DesktopNavigation.module.css b/packages/circuit-ui/components/SideNavigation/components/DesktopNavigation/DesktopNavigation.module.css
index 4c649cd1c4..ecd8869d35 100644
--- a/packages/circuit-ui/components/SideNavigation/components/DesktopNavigation/DesktopNavigation.module.css
+++ b/packages/circuit-ui/components/SideNavigation/components/DesktopNavigation/DesktopNavigation.module.css
@@ -30,7 +30,7 @@
   z-index: var(--cui-z-index-navigation);
   display: flex;
   flex-direction: column;
-  width: var(--cui-icon-sizes-tera);
+  width: var(--cui-icon-sizes-xl);
   height: calc(100vh - var(--top-navigation-height, 0px));
 
   /* biome-ignore lint/suspicious/noDuplicateProperties: Browser compatibility */
diff --git a/packages/circuit-ui/components/SideNavigation/components/PrimaryLink/PrimaryLink.module.css b/packages/circuit-ui/components/SideNavigation/components/PrimaryLink/PrimaryLink.module.css
index 49ae68767a..babf2a0a6b 100644
--- a/packages/circuit-ui/components/SideNavigation/components/PrimaryLink/PrimaryLink.module.css
+++ b/packages/circuit-ui/components/SideNavigation/components/PrimaryLink/PrimaryLink.module.css
@@ -97,8 +97,8 @@
 .icon {
   position: relative;
   flex-shrink: 0;
-  width: var(--cui-icon-sizes-mega);
-  height: var(--cui-icon-sizes-mega);
+  width: var(--cui-icon-sizes-m);
+  height: var(--cui-icon-sizes-m);
   margin-right: var(--cui-spacings-kilo);
 }
 
@@ -150,8 +150,8 @@
 
 .suffix {
   flex-shrink: 0;
-  width: var(--cui-icon-sizes-mega);
-  height: var(--cui-icon-sizes-mega);
+  width: var(--cui-icon-sizes-m);
+  height: var(--cui-icon-sizes-m);
   margin-left: auto;
   transition: transform var(--cui-transitions-default);
 }
diff --git a/packages/circuit-ui/components/Spinner/Spinner.module.css b/packages/circuit-ui/components/Spinner/Spinner.module.css
index ae85249824..28358d278f 100644
--- a/packages/circuit-ui/components/Spinner/Spinner.module.css
+++ b/packages/circuit-ui/components/Spinner/Spinner.module.css
@@ -18,16 +18,16 @@
 }
 
 .s {
-  width: var(--cui-icon-sizes-mega);
-  height: var(--cui-icon-sizes-mega);
+  width: var(--cui-icon-sizes-m);
+  height: var(--cui-icon-sizes-m);
 }
 
 .m {
-  width: var(--cui-icon-sizes-giga);
-  height: var(--cui-icon-sizes-giga);
+  width: var(--cui-icon-sizes-l);
+  height: var(--cui-icon-sizes-l);
 }
 
 .l {
-  width: var(--cui-icon-sizes-tera);
-  height: var(--cui-icon-sizes-tera);
+  width: var(--cui-icon-sizes-xl);
+  height: var(--cui-icon-sizes-xl);
 }
diff --git a/packages/circuit-ui/components/SumUpLogo/SumUpLogo.module.css b/packages/circuit-ui/components/SumUpLogo/SumUpLogo.module.css
index 95cc2456bd..0eedc4b045 100644
--- a/packages/circuit-ui/components/SumUpLogo/SumUpLogo.module.css
+++ b/packages/circuit-ui/components/SumUpLogo/SumUpLogo.module.css
@@ -9,13 +9,13 @@
 
 /* Sizes */
 .s {
-  height: var(--cui-icon-sizes-mega);
+  height: var(--cui-icon-sizes-m);
 }
 
 .m {
-  height: var(--cui-icon-sizes-giga);
+  height: var(--cui-icon-sizes-l);
 }
 
 .l {
-  height: var(--cui-icon-sizes-tera);
+  height: var(--cui-icon-sizes-xl);
 }
diff --git a/packages/circuit-ui/components/TopNavigation/TopNavigation.module.css b/packages/circuit-ui/components/TopNavigation/TopNavigation.module.css
index 19c4842985..46fe314a75 100644
--- a/packages/circuit-ui/components/TopNavigation/TopNavigation.module.css
+++ b/packages/circuit-ui/components/TopNavigation/TopNavigation.module.css
@@ -69,6 +69,6 @@ button.hamburger {
 }
 
 .logo svg {
-  height: var(--cui-icon-sizes-mega);
+  height: var(--cui-icon-sizes-m);
   color: var(--cui-fg-normal);
 }
diff --git a/packages/circuit-ui/components/TopNavigation/components/UtilityLinks/UtilityLinks.module.css b/packages/circuit-ui/components/TopNavigation/components/UtilityLinks/UtilityLinks.module.css
index 2d497bcf55..aaec6207b8 100644
--- a/packages/circuit-ui/components/TopNavigation/components/UtilityLinks/UtilityLinks.module.css
+++ b/packages/circuit-ui/components/TopNavigation/components/UtilityLinks/UtilityLinks.module.css
@@ -19,8 +19,8 @@
 
 .icon {
   flex-shrink: 0;
-  width: var(--cui-icon-sizes-mega);
-  height: var(--cui-icon-sizes-mega);
+  width: var(--cui-icon-sizes-m);
+  height: var(--cui-icon-sizes-m);
 }
 
 @media (min-width: 480px) {
diff --git a/packages/design-tokens/themes/schema.ts b/packages/design-tokens/themes/schema.ts
index 1f517e68e9..d4d7559c51 100644
--- a/packages/design-tokens/themes/schema.ts
+++ b/packages/design-tokens/themes/schema.ts
@@ -221,10 +221,32 @@ export const schema = [
   { name: '--cui-font-weight-semibold', type: 'fontWeight' },
   { name: '--cui-font-weight-bold', type: 'fontWeight' },
   /* Icon sizes */
-  { name: '--cui-icon-sizes-kilo', type: 'dimension' },
-  { name: '--cui-icon-sizes-mega', type: 'dimension' },
-  { name: '--cui-icon-sizes-giga', type: 'dimension' },
-  { name: '--cui-icon-sizes-tera', type: 'dimension' },
+  { name: '--cui-icon-sizes-s', type: 'dimension' },
+  { name: '--cui-icon-sizes-m', type: 'dimension' },
+  { name: '--cui-icon-sizes-l', type: 'dimension' },
+  { name: '--cui-icon-sizes-xl', type: 'dimension' },
+  /* eslint-disable circuit-ui/no-deprecated-custom-properties */
+  {
+    name: '--cui-icon-sizes-kilo',
+    type: 'dimension',
+    deprecation: { replacement: '--cui-icon-sizes-s' },
+  },
+  {
+    name: '--cui-icon-sizes-mega',
+    type: 'dimension',
+    deprecation: { replacement: '--cui-icon-sizes-m' },
+  },
+  {
+    name: '--cui-icon-sizes-giga',
+    type: 'dimension',
+    deprecation: { replacement: '--cui-icon-sizes-l' },
+  },
+  {
+    name: '--cui-icon-sizes-tera',
+    type: 'dimension',
+    deprecation: { replacement: '--cui-icon-sizes-xl' },
+  },
+  /* eslint-enable circuit-ui/no-deprecated-custom-properties */
   /* Spacings */
   { name: '--cui-spacings-bit', type: 'dimension' },
   { name: '--cui-spacings-byte', type: 'dimension' },
diff --git a/packages/design-tokens/themes/shared.ts b/packages/design-tokens/themes/shared.ts
index 06a5200e76..fbd648ecc5 100644
--- a/packages/design-tokens/themes/shared.ts
+++ b/packages/design-tokens/themes/shared.ts
@@ -120,6 +120,27 @@ export const shared = [
     type: 'dimension',
   },
   /* Icon sizes */
+  {
+    name: '--cui-icon-sizes-s',
+    value: '1rem',
+    type: 'dimension',
+  },
+  {
+    name: '--cui-icon-sizes-m',
+    value: '1.5rem',
+    type: 'dimension',
+  },
+  {
+    name: '--cui-icon-sizes-l',
+    value: '2rem',
+    type: 'dimension',
+  },
+  {
+    name: '--cui-icon-sizes-xl',
+    value: '3rem',
+    type: 'dimension',
+  },
+  /* eslint-disable circuit-ui/no-deprecated-custom-properties */
   {
     name: '--cui-icon-sizes-kilo',
     value: '16px',
@@ -140,6 +161,7 @@ export const shared = [
     value: '48px',
     type: 'dimension',
   },
+  /* eslint-enable circuit-ui/no-deprecated-custom-properties */
   /* Spacings */
   {
     name: '--cui-spacings-bit',
diff --git a/skills/circuit-ui/references/design-tokens.md b/skills/circuit-ui/references/design-tokens.md
index 640bc08ef8..fb486dca4e 100644
--- a/skills/circuit-ui/references/design-tokens.md
+++ b/skills/circuit-ui/references/design-tokens.md
@@ -180,10 +180,10 @@ CSS variables provided by the Circuit UI design system and their values.
 | `--cui-font-weight-regular` | `fontWeight` | no |  | `375` | `375` |
 | `--cui-font-weight-semibold` | `fontWeight` | no |  | `550` | `550` |
 | `--cui-font-weight-bold` | `fontWeight` | no |  | `650` | `650` |
-| `--cui-icon-sizes-kilo` | `dimension` | no |  | `16px` | `16px` |
-| `--cui-icon-sizes-mega` | `dimension` | no |  | `24px` | `24px` |
-| `--cui-icon-sizes-giga` | `dimension` | no |  | `32px` | `32px` |
-| `--cui-icon-sizes-tera` | `dimension` | no |  | `48px` | `48px` |
+| `--cui-icon-sizes-s` | `dimension` | no |  | `1rem` | `1rem` |
+| `--cui-icon-sizes-m` | `dimension` | no |  | `1.5rem` | `1.5rem` |
+| `--cui-icon-sizes-l` | `dimension` | no |  | `2rem` | `2rem` |
+| `--cui-icon-sizes-xl` | `dimension` | no |  | `3rem` | `3rem` |
 | `--cui-spacings-bit` | `dimension` | no |  | `4px` | `4px` |
 | `--cui-spacings-byte` | `dimension` | no |  | `8px` | `8px` |
 | `--cui-spacings-kilo` | `dimension` | no |  | `12px` | `12px` |