diff --git a/frontend/cypress/e2e/mainnet/calculator.spec.ts b/frontend/cypress/e2e/mainnet/calculator.spec.ts
index b09dff154..6866873fe 100644
--- a/frontend/cypress/e2e/mainnet/calculator.spec.ts
+++ b/frontend/cypress/e2e/mainnet/calculator.spec.ts
@@ -83,22 +83,28 @@ describe('Calculator', () => {
     });
 
     describe('bitcoin input updates fiat and sats', () => {
-      it('updates fiat and sats when entering 0.5 BTC', () => {
-        const expectedFiat = Math.round(MOCK_BTC_PRICE_USD * 0.5 * 100) / 100;
-        cy.get('input[formControlName="bitcoin"]').clear().type('0.5');
-        cy.get('input[formControlName="satoshis"]').invoke('val').should('equal', '50000000');
+      it('updates fiat and sats when entering 0.33 BTC', () => {
+        const expectedFiat = Math.round(MOCK_BTC_PRICE_USD * 0.33 * 100) / 100; // 40740.48 USD
+        cy.get('input[formControlName="bitcoin"]').clear().type('0.33');
+        cy.get('input[formControlName="satoshis"]').invoke('val').should('equal', '33000000');
         cy.get('input[formControlName="fiat"]').invoke('val').then((fiatVal) => {
           const fiat = parseFloat(String(fiatVal).replace(/,/g, ''));
           expect(fiat).to.equal(expectedFiat);
         });
+        cy.get('.fiat-text').invoke('text').then((text) => {
+          expect(text.trim()).to.equal('$40,740.48');
+        });
       });
 
       it('updates fiat and sats when entering 1 sat (0.00000001 BTC)', () => {
-        const expectedFiat = (MOCK_BTC_PRICE_USD / 100_000_000 * 100 / 100).toFixed(8);
+        const expectedFiat = (MOCK_BTC_PRICE_USD / 100_000_000 * 100 / 100);
         cy.get('input[formControlName="bitcoin"]').clear().type('0.00000001');
         cy.get('input[formControlName="satoshis"]').invoke('val').should('equal', '1');
         cy.get('input[formControlName="fiat"]').invoke('val').then((fiatVal) => {
-          expect(String(fiatVal)).to.equal(expectedFiat);
+          expect(String(fiatVal)).to.equal(String(expectedFiat));
+        });
+        cy.get('.fiat-text').invoke('text').then((text) => {
+          expect(text.trim()).to.equal('$0.00');
         });
       });
     });
@@ -220,6 +226,9 @@ describe('Calculator', () => {
         cy.get('.symbol').invoke('text').then((text) => {
           expect(text.replace(/,/g, '')).to.include(String(MOCK_BTC_PRICE_JPY));
         });
+        cy.get('.fiat-text').invoke('text').then((text) => {
+          expect(text.trim()).to.equal('¥11,057,757');
+        });
       });
 
       it('displays 1 BTC with correct sats and fiat in JPY', () => {
@@ -234,13 +243,17 @@ describe('Calculator', () => {
       });
 
       it('updates fiat and sats when entering 0.5 BTC in JPY', () => {
-        const expectedFiat = Math.round(MOCK_BTC_PRICE_JPY * 0.5 * 100) / 100;
+        const expectedFiat = Math.round(MOCK_BTC_PRICE_JPY * 0.5)
         cy.get('input[formControlName="bitcoin"]').clear().type('0.5');
         cy.get('input[formControlName="satoshis"]').invoke('val').should('equal', '50000000');
         cy.get('input[formControlName="fiat"]').invoke('val').then((fiatVal) => {
           const fiat = parseFloat(String(fiatVal).replace(/,/g, ''));
           expect(fiat).to.equal(expectedFiat);
         });
+        cy.get('.fiat-text').invoke('text').then((text) => {
+          expect(text.trim()).to.equal('¥5,528,879');
+        });
+
       });
 
       it('updates BTC and sats when entering fiat value in JPY', () => {
@@ -258,13 +271,16 @@ describe('Calculator', () => {
 
       it('updates BTC and fiat when entering 10000 sats in JPY', () => {
         const satsAmount = 10000;
-        const expectedFiat = Math.round((satsAmount / 100_000_000) * MOCK_BTC_PRICE_JPY * 100) / 100;
+        const expectedFiat = Math.round((satsAmount / 100_000_000) * MOCK_BTC_PRICE_JPY);
         cy.get('input[formControlName="satoshis"]').clear().type(String(satsAmount));
         cy.get('input[formControlName="bitcoin"]').invoke('val').should('equal', '0.00010000');
         cy.get('input[formControlName="fiat"]').invoke('val').then((fiatVal) => {
           const fiat = parseFloat(String(fiatVal).replace(/,/g, ''));
           expect(fiat).to.equal(expectedFiat);
         });
+        cy.get('.fiat-text').invoke('text').then((text) => {
+          expect(text.trim()).to.equal('¥1,106');
+        });
       });
     });
 
diff --git a/frontend/cypress/e2e/mainnet/fiat-currency-formatting.spec.ts b/frontend/cypress/e2e/mainnet/fiat-currency-formatting.spec.ts
new file mode 100644
index 000000000..90e17d032
--- /dev/null
+++ b/frontend/cypress/e2e/mainnet/fiat-currency-formatting.spec.ts
@@ -0,0 +1,275 @@
+const baseModule = Cypress.env('BASE_MODULE');
+
+// Helper to select "Fiat" from the BTC/sats/Fiat amount selector dropdown
+const selectFiatMode = () => {
+  cy.get('app-amount-selector').first().scrollIntoView();
+  cy.get('app-amount-selector select').first().select('fiat');
+};
+
+// Helper to select currency from the fiat selector dropdown
+const selectCurrency = (currency: 'USD' | 'JPY') => {
+  cy.get('app-fiat-selector').first().scrollIntoView();
+  cy.get('app-fiat-selector').first().click();
+  cy.get('app-fiat-selector select').first().select(currency);
+};
+
+describe('Fiat Currency Formatting', () => {
+
+  if (baseModule === 'mempool') {
+
+    describe('Dashboard', () => {
+      beforeEach(() => {
+        cy.visit('/');
+        cy.waitForSkeletonGone();
+        selectFiatMode();
+        cy.get('.latest-transactions', { timeout: 10000 }).should('exist');
+        cy.get('.table-cell-fiat', { timeout: 10000 }).should('have.length.at.least', 1);
+      });
+
+      describe('USD formatting', () => {
+        beforeEach(() => {
+          selectCurrency('USD');
+        });
+
+        it('displays USD values with correct currency symbol', () => {
+          cy.get('.table-cell-fiat').eq(1).invoke('text').then((text) => {
+            const trimmedText = text.trim();
+            expect(trimmedText).to.include('$');
+          });
+        });
+
+        it('displays USD values with proper decimal format', () => {
+          cy.get('.table-cell-fiat').eq(1).invoke('text').then((text) => {
+            const trimmedText = text.trim();
+            expect(trimmedText).to.match(/^\$[\d,]+(\.\d{2})?$/);
+          });
+        });
+      });
+
+      describe('JPY formatting', () => {
+        beforeEach(() => {
+          selectCurrency('JPY');
+          cy.get('.table-cell-fiat').eq(1).should(($el) => {
+            expect($el.text()).to.include('¥');
+          });
+        });
+
+        it('displays JPY values with yen symbol', () => {
+          cy.get('.table-cell-fiat').eq(1).invoke('text').then((text) => {
+            const trimmedText = text.trim();
+            expect(trimmedText).to.include('¥');
+          });
+        });
+
+        it('displays JPY values without decimal places', () => {
+          cy.get('.table-cell-fiat').eq(1).invoke('text').then((text) => {
+            const trimmedText = text.trim();
+            expect(trimmedText).to.not.match(/\.\d+$/);
+          });
+        });
+
+        it('formats all JPY values correctly without decimals', () => {
+          cy.get('.table-cell-fiat').each(($el) => {
+            const text = $el.text().trim();
+            if (text.includes('¥')) {
+              expect(text).to.not.match(/\.\d+/);
+            }
+          });
+        });
+      });
+
+      describe('currency switching', () => {
+        it('correctly formats when switching from USD to JPY', () => {
+          selectCurrency('USD');
+          cy.get('.table-cell-fiat').eq(1).invoke('text').then((usdText) => {
+            expect(usdText.trim()).to.include('$');
+          });
+
+          selectCurrency('JPY');
+          cy.get('.table-cell-fiat').eq(1).should(($el) => {
+            const text = $el.text().trim();
+            expect(text).to.include('¥');
+            expect(text).to.not.match(/\.\d+$/);
+          });
+        });
+
+        it('correctly formats when switching from JPY back to USD', () => {
+          selectCurrency('JPY');
+          cy.get('.table-cell-fiat').eq(1).should(($el) => {
+            expect($el.text()).to.include('¥');
+          });
+
+          selectCurrency('USD');
+          cy.get('.table-cell-fiat').eq(1).should(($el) => {
+            expect($el.text().trim()).to.include('$');
+          });
+        });
+      });
+    });
+
+    describe('Transaction Page', () => {
+      beforeEach(() => {
+        cy.visit('/tx/dd0faea1e9acd5bd812e5130c0912b62d6b63d04bac4558f2e07270ac613a8f2');
+        cy.waitForSkeletonGone();
+      });
+
+      it('displays USD fiat values with dollar symbol', () => {
+        selectCurrency('USD');
+        selectFiatMode();
+
+        cy.get('app-transaction-details .fiat').invoke('text').then((text) => {
+          expect(text.trim()).to.include('$');
+        });
+
+        cy.get('app-transactions-list .fiat', { timeout: 10000 }).first().invoke('text').then((text) => {
+          expect(text.trim()).to.include('$');
+        });
+      });
+
+      it('displays JPY fiat values without decimals', () => {
+        selectCurrency('JPY');
+        selectFiatMode();
+
+
+        cy.get('app-transaction-details .fiat').invoke('text').then((text) => {
+          const trimmedText = text.trim();
+          expect(trimmedText).to.include('¥');
+          expect(trimmedText).to.not.match(/\.\d+/);
+        });
+
+        cy.get('app-transactions-list .fiat').first().should(($el) => {
+          const text = $el.text().trim();
+          expect(text).to.include('¥');
+          expect(text).to.not.match(/\.\d+/);
+        });
+      });
+    });
+
+    describe('Block Page', () => {
+      beforeEach(() => {
+        cy.viewport(1080, 1920); // force taller screen to avoid scrollbars
+        cy.intercept('/api/v1/blocks/0').as('blocks-0');
+        cy.intercept('/api/v1/blocks/10').as('blocks-10');
+        cy.intercept('/api/v1/blocks/20').as('blocks-20');
+        cy.intercept('/api/txs/outspends*').as('outspends');
+        cy.visit('/block/100000');
+      });
+
+      it('displays USD fiat values in block reward with dollar symbol', () => {
+        cy.wait('@outspends').then(() => {
+          cy.waitUntil(() => cy.get('.fiat').each(($el) => $el.is(':visible') && $el.text().trim().includes('$')));
+          selectCurrency('USD');
+          selectFiatMode();
+          cy.get('.fiat').each(($el) => {
+            expect($el.text().trim()).to.include('$');
+          });
+        });
+      });
+    
+    it('displays JPY fiat values without decimals', () => {
+        cy.wait('@outspends').then(() => {
+          cy.waitUntil(() => cy.get('.fiat').each(($el) => $el.is(':visible') && $el.text().trim().includes('$')));
+          selectCurrency('JPY');
+          selectFiatMode();
+          cy.get('.fiat').each(($el) => {
+            expect($el.text().trim()).to.include('¥');
+            expect($el.text().trim()).to.not.match(/\.\d+/);
+          });
+        });        
+    })
+  });
+  
+    describe('Address Page', () => {
+      beforeEach(() => {
+        cy.visit('/address/1wizaAB16Wrua9V58uNvqktyq2LBLtYso');
+      });
+
+      it('displays USD fiat values with dollar symbol', () => {
+        selectCurrency('USD');
+        selectFiatMode();
+        cy.get('app-amount .fiat', { timeout: 10000 }).each(($el) => {
+          expect($el.text().trim()).to.include('$');
+        });
+      });
+
+      it('displays JPY fiat values without decimals', () => {
+        selectCurrency('JPY');
+        selectFiatMode();
+        cy.get('app-amount .fiat').first().should(($el) => {
+          const text = $el.text().trim();
+          expect(text).to.include('¥');
+          expect(text).to.not.match(/\.\d+/);
+        });
+      });
+    });
+
+    describe('Calculator Page', () => {
+      beforeEach(() => {
+        cy.visit('/tools/calculator');
+        cy.waitForSkeletonGone();
+        cy.get('input[formControlName="bitcoin"]', { timeout: 10000 }).should('be.visible');
+      });
+
+      it('displays USD price with dollar symbol', () => {
+        selectCurrency('USD');
+        cy.get('.symbol').invoke('text').then((text) => {
+          expect(text.trim()).to.include('$');
+        });
+      });
+
+      it('displays JPY price without decimals after switching currency', () => {
+        selectCurrency('JPY');
+        cy.get('.symbol').should(($el) => {
+          const text = $el.text().trim();
+          expect(text).to.include('¥');
+        });
+
+        // Enter a value in BTC to see the fiat conversion
+        cy.get('input[formControlName="bitcoin"]').clear().type('1');
+
+        // Check that the fiat output doesn't have decimals for JPY
+        cy.get('input[formControlName="fiat"]').should(($el) => {
+          const value = $el.val() as string;
+          // JPY should not have decimal places in large values
+          expect(value).to.not.match(/\.\d+$/);
+        });
+      });
+    });
+
+    describe('Mempool Block Tooltip', () => {
+      beforeEach(() => {
+        cy.visit('/');
+        cy.waitForSkeletonGone();
+        selectFiatMode();
+      });
+
+      it('displays USD fiat values in mempool block', () => {
+        selectCurrency('USD');
+        cy.get('#mempool-block-0').scrollIntoView();
+        cy.get('#mempool-block-0').click();
+
+        cy.waitForSkeletonGone();
+
+        cy.get('app-mempool-block .fiat').each(($el) => {
+          expect($el.text().trim()).to.include('$');
+        });
+      });
+
+      it('displays JPY fiat values in mempool block', () => {
+        selectCurrency('JPY');
+        cy.get('#mempool-block-0').scrollIntoView();
+        cy.get('#mempool-block-0').click();
+
+        cy.waitForSkeletonGone();
+
+        cy.get('app-mempool-block .fiat').invoke('text').then((text) => {
+          expect(text.trim()).to.include('¥');
+          expect(text).to.not.match(/\.\d+$/);
+        });
+      });
+    });
+
+  } else {
+    it.skip(`Tests cannot be run on the selected BASE_MODULE ${baseModule}`);
+  }
+});
diff --git a/frontend/src/app/components/calculator/calculator.component.ts b/frontend/src/app/components/calculator/calculator.component.ts
index d38039d37..5d749bc7b 100644
--- a/frontend/src/app/components/calculator/calculator.component.ts
+++ b/frontend/src/app/components/calculator/calculator.component.ts
@@ -1,4 +1,4 @@
-import { ChangeDetectionStrategy, Component, OnInit } from '@angular/core';
+import { ChangeDetectionStrategy, Component, Inject, LOCALE_ID, OnInit } from '@angular/core';
 import { FormBuilder, FormGroup } from '@angular/forms';
 import { combineLatest, Observable } from 'rxjs';
 import { map, switchMap } from 'rxjs/operators';
@@ -20,12 +20,15 @@ export class CalculatorComponent implements OnInit {
   form: FormGroup;
   currentPrice = 0;
   isMaxSupply = false;
+  currentCurrency = 'USD';
+  currencyDecimals = 2;
 
   currency$ = this.stateService.fiatCurrency$;
   price$: Observable<number>;
   lastFiatPrice$: Observable<number>;
 
   constructor(
+    @Inject(LOCALE_ID) private locale: string,
     private stateService: StateService,
     private formBuilder: FormBuilder,
     private websocketService: WebsocketService,
@@ -47,6 +50,8 @@ export class CalculatorComponent implements OnInit {
     this.price$ = this.currency$.pipe(
       switchMap((result) => {
         currency = result;
+        this.currentCurrency = result;
+        this.updateCurrencyDecimals();
         return this.stateService.conversions$.asObservable();
       }),
       map((conversions) => {
@@ -132,8 +137,11 @@ export class CalculatorComponent implements OnInit {
     if (name === 'bitcoin' && this.countDecimals(sanitizedValue) > 8) {
       sanitizedValue = this.toFixedWithoutRounding(sanitizedValue, 8);
     }
-    if (name === 'fiat' && this.countDecimals(sanitizedValue) > 2) {
-      sanitizedValue = this.toFixedWithoutRounding(sanitizedValue, 2);
+    if (name === 'fiat') {
+      const decimals = this.getCurrencyDecimals();
+      if (this.countDecimals(sanitizedValue) > decimals) {
+        sanitizedValue = this.toFixedWithoutRounding(sanitizedValue, decimals);
+      }
     }
     if (sanitizedValue === '') {
       sanitizedValue = '0';
@@ -176,12 +184,20 @@ export class CalculatorComponent implements OnInit {
   }
 
   formatFiat(num: number): string | number {
+    // Get the number of decimal places for the current currency
+    const decimals = this.getCurrencyDecimals();
+
+    if (decimals === 0) {
+      return Math.round(num);
+    }
+
     if (Math.abs(num) >= 1000) {
-      // For values >= 1000: show 2 decimals, or 0 if whole number
+      // For values >= 1000: show currency-specific decimals, or 0 if whole number
       if (num % 1 === 0) {
         return Math.round(num);
       }
-      return (Math.round(num * 100) / 100).toFixed(2);
+      const factor = Math.pow(10, decimals);
+      return (Math.round(num * factor) / factor).toFixed(decimals);
     }
     if (num % 1 === 0) {
       return Math.round(num);
@@ -190,6 +206,23 @@ export class CalculatorComponent implements OnInit {
     if (Math.abs(num) < 1 && num !== 0) {
       return num.toFixed(8);
     }
-    return (Math.round(num * 100) / 100).toFixed(2);
+    const factor = Math.pow(10, decimals);
+    return (Math.round(num * factor) / factor).toFixed(decimals);
+  }
+
+  private updateCurrencyDecimals(): void {
+    try {
+      const formatter = new Intl.NumberFormat(this.locale, {
+        style: 'currency',
+        currency: this.currentCurrency
+      });
+      this.currencyDecimals = formatter.resolvedOptions().maximumFractionDigits;
+    } catch {
+      this.currencyDecimals = 2; // Default to 2 decimal places
+    }
+  }
+
+  getCurrencyDecimals(): number {
+    return this.currencyDecimals;
   }
 }
diff --git a/frontend/src/app/shared/pipes/fiat-currency.pipe.ts b/frontend/src/app/shared/pipes/fiat-currency.pipe.ts
index ffaef26d3..b3f3cb193 100644
--- a/frontend/src/app/shared/pipes/fiat-currency.pipe.ts
+++ b/frontend/src/app/shared/pipes/fiat-currency.pipe.ts
@@ -21,17 +21,7 @@ export class FiatCurrencyPipe implements PipeTransform {
   }
 
   transform(num: number, ...args: any[]): unknown {
-    const digits = args[0] || 1;
     const currency = args[1] || this.currency || 'USD';
-
-    if (Math.abs(num) >= 1000) {
-      // Check if decimals are exactly 0
-      if (num % 1 === 0) {
-        return new Intl.NumberFormat(this.locale, { style: 'currency', currency, maximumFractionDigits: 0 }).format(num);
-      }
-      return new Intl.NumberFormat(this.locale, { style: 'currency', currency, minimumFractionDigits: 2, maximumFractionDigits: 2 }).format(num);
-    } else {
-      return new Intl.NumberFormat(this.locale, { style: 'currency', currency }).format(num);
-    }
+    return new Intl.NumberFormat(this.locale, { style: 'currency', currency }).format(num);
   }
 }