diff --git a/satellite/payments/projectcharges.go b/satellite/payments/projectcharges.go
index 50e5daaea..8e501ce6f 100644
--- a/satellite/payments/projectcharges.go
+++ b/satellite/payments/projectcharges.go
@@ -14,12 +14,12 @@ import (
 type ProjectCharge struct {
 	accounting.ProjectUsage
 
-	// StorageGbHrs shows how much cents we should pay for storing GB*Hrs.
-	StorageGbHrs int64 `json:"storagePrice"`
-	// Egress shows how many cents we should pay for Egress.
-	Egress int64 `json:"egressPrice"`
-	// SegmentCount shows how many cents we should pay for objects count.
-	SegmentCount int64 `json:"segmentPrice"`
+	// StorageMBMonthCents is how many cents we should pay for storing MB*months.
+	StorageMBMonthCents int64 `json:"storagePrice"`
+	// EgressMBCents is how many cents we should pay for megabytes of egress.
+	EgressMBCents int64 `json:"egressPrice"`
+	// SegmentMonthCents is how many cents we should pay for objects count.
+	SegmentMonthCents int64 `json:"segmentPrice"`
 }
 
 // ProjectChargesResponse represents a collection of project usage charges grouped by project ID and partner name.
diff --git a/satellite/payments/stripe/accounts.go b/satellite/payments/stripe/accounts.go
index a924ebc1a..e2f431317 100644
--- a/satellite/payments/stripe/accounts.go
+++ b/satellite/payments/stripe/accounts.go
@@ -146,14 +146,15 @@ func (accounts *accounts) ProjectCharges(ctx context.Context, userID uuid.UUID,
 
 		for partner, usage := range usages {
 			priceModel := accounts.GetProjectUsagePriceModel(partner)
-			price := accounts.service.calculateProjectUsagePrice(usage.Egress, usage.Storage, usage.SegmentCount, priceModel)
+			usage.Egress = applyEgressDiscount(usage, priceModel)
+			price := accounts.service.calculateProjectUsagePrice(usage, priceModel)
 
 			partnerCharges[partner] = payments.ProjectCharge{
 				ProjectUsage: usage,
 
-				Egress:       price.Egress.IntPart(),
-				SegmentCount: price.Segments.IntPart(),
-				StorageGbHrs: price.Storage.IntPart(),
+				EgressMBCents:       price.Egress.IntPart(),
+				SegmentMonthCents:   price.Segments.IntPart(),
+				StorageMBMonthCents: price.Storage.IntPart(),
 			}
 		}
 
diff --git a/satellite/payments/stripe/service.go b/satellite/payments/stripe/service.go
index 1afcfa729..f0db054f0 100644
--- a/satellite/payments/stripe/service.go
+++ b/satellite/payments/stripe/service.go
@@ -539,10 +539,7 @@ func (service *Service) InvoiceItemsFromProjectUsage(projName string, partnerUsa
 		priceModel := service.Accounts().GetProjectUsagePriceModel(partner)
 
 		usage := partnerUsages[partner]
-		usage.Egress -= int64(math.Round(usage.Storage / hoursPerMonth * priceModel.EgressDiscountRatio))
-		if usage.Egress < 0 {
-			usage.Egress = 0
-		}
+		usage.Egress = applyEgressDiscount(usage, priceModel)
 
 		prefix := "Project " + projName
 		if partner != "" {
@@ -891,11 +888,11 @@ func (price projectUsagePrice) TotalInt64() int64 {
 }
 
 // calculateProjectUsagePrice calculate project usage price.
-func (service *Service) calculateProjectUsagePrice(egress int64, storage, segments float64, pricing payments.ProjectUsagePriceModel) projectUsagePrice {
+func (service *Service) calculateProjectUsagePrice(usage accounting.ProjectUsage, pricing payments.ProjectUsagePriceModel) projectUsagePrice {
 	return projectUsagePrice{
-		Storage:  pricing.StorageMBMonthCents.Mul(storageMBMonthDecimal(storage)).Round(0),
-		Egress:   pricing.EgressMBCents.Mul(egressMBDecimal(egress)).Round(0),
-		Segments: pricing.SegmentMonthCents.Mul(segmentMonthDecimal(segments)).Round(0),
+		Storage:  pricing.StorageMBMonthCents.Mul(storageMBMonthDecimal(usage.Storage)).Round(0),
+		Egress:   pricing.EgressMBCents.Mul(egressMBDecimal(usage.Egress)).Round(0),
+		Segments: pricing.SegmentMonthCents.Mul(segmentMonthDecimal(usage.SegmentCount)).Round(0),
 	}
 }
 
@@ -928,3 +925,13 @@ func segmentMonthDecimal(segments float64) decimal.Decimal {
 func doesProjectRecordHaveNoUsage(record ProjectRecord) bool {
 	return record.Storage == 0 && record.Egress == 0 && record.Segments == 0
 }
+
+// applyEgressDiscount returns the amount of egress that we should charge for by subtracting
+// the discounted amount.
+func applyEgressDiscount(usage accounting.ProjectUsage, model payments.ProjectUsagePriceModel) int64 {
+	egress := usage.Egress - int64(math.Round(usage.Storage/hoursPerMonth*model.EgressDiscountRatio))
+	if egress < 0 {
+		egress = 0
+	}
+	return egress
+}