diff --git a/hw/block/nvme.c b/hw/block/nvme.c
index 87f1f0d0d1..3f3db17231 100644
--- a/hw/block/nvme.c
+++ b/hw/block/nvme.c
@@ -1573,8 +1573,7 @@ static void nvme_realize(PCIDevice *pci_dev, Error **errp)
         id_ns->dps = 0;
         id_ns->lbaf[0].ds = BDRV_SECTOR_BITS;
         id_ns->ncap  = id_ns->nuse = id_ns->nsze =
-            cpu_to_le64(n->ns_size >>
-                id_ns->lbaf[NVME_ID_NS_FLBAS_INDEX(ns->id_ns.flbas)].ds);
+            cpu_to_le64(nvme_ns_nlbas(n, ns));
     }
 }
 
diff --git a/hw/block/nvme.h b/hw/block/nvme.h
index cedc8022db..61dd9b23b8 100644
--- a/hw/block/nvme.h
+++ b/hw/block/nvme.h
@@ -61,6 +61,17 @@ typedef struct NvmeNamespace {
     NvmeIdNs        id_ns;
 } NvmeNamespace;
 
+static inline NvmeLBAF *nvme_ns_lbaf(NvmeNamespace *ns)
+{
+    NvmeIdNs *id_ns = &ns->id_ns;
+    return &id_ns->lbaf[NVME_ID_NS_FLBAS_INDEX(id_ns->flbas)];
+}
+
+static inline uint8_t nvme_ns_lbads(NvmeNamespace *ns)
+{
+    return nvme_ns_lbaf(ns)->ds;
+}
+
 #define TYPE_NVME "nvme"
 #define NVME(obj) \
         OBJECT_CHECK(NvmeCtrl, (obj), TYPE_NVME)
@@ -97,4 +108,10 @@ typedef struct NvmeCtrl {
     NvmeIdCtrl      id_ctrl;
 } NvmeCtrl;
 
+/* calculate the number of LBAs that the namespace can accomodate */
+static inline uint64_t nvme_ns_nlbas(NvmeCtrl *n, NvmeNamespace *ns)
+{
+    return n->ns_size >> nvme_ns_lbads(ns);
+}
+
 #endif /* HW_NVME_H */